(Note: This Letter, from Dan, Is continued from Page 13)
HISTORICAL JESUS/HISTORICAL METHOD:
You say: Modern historians and scholars don't start with the assumption that much of what is in the text is false.
Problem: No, but they don’t start with the assumption that much of what is in the text is true, either. What they do is verify the claims of documents against other documents talking about the same event, if there are any around, while also determine possible bias.
You say: Compare (John’s sermon) to Matthew 7:17-19: " Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.  A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit.  Every tree that bringeth not forth good fruit is hewn down, and cast into the fire." As with what John the Baptist is saying, the good fruit is the *result* of being (figuratively speaking) a good tree. John talks about producing good fruit *in keeping with repentance*. Bringing forth good fruit cannot, in and of itself, save you, since you cannot bring forth good fruit unless you're already saved (a good tree).
Problem: Your interpretation of Matthew is way wrong. You are claiming that everybody is already a “good tree” or “bad tree” and that the fruit is a result of already being a good/bad tree. You are ignoring the context of these verses by omitting a whole bunch of surrounding verses – talk about cherry picking! This is a parable about deceptive appearances(7:15-16), and how to tell the difference between a liar and a good man. It is not a parable about becoming saved and then doing good work – that’s your Christian brain at work again. “Tree” represents how a person is perceived outwardly – for example, a Pharisee might be generally viewed as a “good tree” since he’s a Jewish leader, and so it’s assumed he produces “good fruit”. However, Jesus warns that there are false prophets (7:15) who LOOK like a good tree (in sheep’s clothing) but are actually a bad tree (inwardly they are ferocious wolves). How can you tell a good tree from a bad tree then, if appearances can be decieving? BY THEIR FRUIT (7:16). The point of this parable is that appearances can be deceiving, and that only by looking at that person’s ACTIONS, or FRUIT, can you tell if they are a good tree or bad tree. The reason Jesus says that a “good tree” can only produce “good fruit,” is because he’s showing how the person’s ACTIONS are directly reflective of that person’s commitment to God. Why can we judge a person soley by their actions? Because good fruit will only come from good trees, and bad fruit will only come from bad trees. If you see what appears to be a good tree (Pharisee) but the fruit it bad, then you know it’s actually a bad tree. This is a parable on deceptive appearances, not some sort of Christian theory on how once you’re “saved,” you’ll only be able to produce “good fruit.” This focus on good works is also verified immediately after the parable when Jesus says:
"Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?' Then I will tell them plainly, 'I never knew you. Away from me, you evildoers!' Matthew 7:21-23
Jesus didn’t care about a person’s personal relationship with him or doing things in his name or proclaiming his glory with prophecies (like the Resurrection)! He cares about you doing the will of the Father – to do good works! You’re once again trying to claim you don’t need to do good works, even though when the crowd asks John “What should we do then?” John directly replies “share your tunic/food with others.” He didn’t say believe in Jesus! He didn’t say believe Jesus will die for your sins! He didn’t say a single word about “believing” in anything actually, he only said to do good works! Your works will be the evidence of your belief: “By their fruit you will recognize them”
You say: Let me ask you this, per your understanding of this passage and what you think Jesus was trying to say, what would happen if I fed one poor person one day, but did nothing kind for anyone else ever again in my life? Would I then be saved?"
Problem: Of course not. This is as ridiculous as saying “What would happen if I believed in Jesus one day, but didn’t ever again for the rest of my life. Would I then be saved?” People needed to continually do good works up until the Kingdom of God arrives, just as Christians believe that one must remain faithful to their belief in Jesus.
You say: Obviously. Are you really saying Jesus is talking about a *literal* gate and road? That He expected his followers to walk off looking for a narrow road that led to a gate? You're the first person I've ever met who has ever implied such.
Problem: I don’t think you understand why I’m using the term figurative. Of course the gate and road represent something other than a gate and road: they are symbolic of the paths to salvation/damnation. I’m asking, do you consider the actual message figurative, that only few will make it into heaven? There’s no reason to discard the meaning of this message simply because it uses symbolic language. The meaning stays literal; the use of symbolic language is only to make the meaning more clear. You said doing good works all the time would be too hard, and here is my backup verse saying, well, yes it is, and not many are gong to make it to heaven.
You say: In other words, you're ignoring anything Jesus said (per the Bible) that conflicts with your view of Jesus in order to limit your understanding of what Jesus was. You have your theory, and are stacking the deck by tossing out anything Jesus said that conflicts with your theory, assuming that those words must have been put into Jesus' mouth after the fact. Once you start dismissing any evidence that goes against your theory, you can pretty much theorize anything you want to and claim it's supported by the evidence.
It's the kind of thing conspiracy theorists do. If evidence in mainstream newspapers conflicts with their theory, then they say that we can't trust the newspapers, that "they're in on it". If government records conflict with their theory - then "of course the government is going to cover it up!". I've debated against Holocaust Deniers, Christ-mythers, and even a guy who believed President Obama was a Muslim, and it's the methods they use, and there's no arguing with them. You're not going to persuade them by showing how the preponderance of the evidence goes against the theory, since they reject any evidence that doesn't support their theory.
Problem: I consider verses less likley to be authentic when they 1) can’t be found in multple, independent early sources, 2) are counter to what we know about the historical context of 1st century Judaism and 3) are strongly in favor of the biographers personal views concerning a hotly contested situation. You reject the apocalyptic Jesus, but it just so happens that the earliest independent sources (Mark/Q/M/L) fully support the historical apocalyptic view while the later sources do not! – but I suppose you’ll label this as some kind of tremendously weird coincidence?
Your comparison of this historical method to conspiracy theories is terribly inaccurate. Do I really need to explain? Sigh. 1) The Gospels are not mainstream newspapers! 2) The Gospels are not government records! You have such a high, inflated view of these Gospels that it seems you’re equating them to today’s versions of record keeping. It’s completely inappropriate.
These are the facts:
1) Apocalyptic Judaism was already established to have existed in 1st century Palestine before even looking at the New Testament.
2) We know that Mark, Q, M and L are four of the earliest sources we can use to talk about Jesus.
3) These early sources fit almost perfectly within the context of the independently-established Apocalyptic Judaism.
4) Later sources fit into more traditional Christian doctrine.
You haven’t disproven a single one of these facts. The only thing you continue to do is spout “Conspiracy theory!” I mean, this method has been rigourusly tested by hundreds of scholars over a hundred years, and is taught in Princeton, and you say Conspiracy Theory? Really, that’s your line of defense?
You say: Again, feel free to accept or reject whatever you want in order to believe what you want to believe, but I've met many non-Christians who agree that Jesus was talking about the destruction of Jerusalem, and even purposely date the Gospels to post-70 AD to explain Jesus' apparent "foreknowledge" of this event.
Problem: What specific verses were talking about the destruction of the temple? Only a few of those apocalyptic passages speak vaguely about it being destroyed. The rest is about “sun will be darkened” “moon not gives its light” “stars fall from the sky” “heavenly bodies will be shaken” “Son of Man will come in clouds” to “gather his elect from the four winds” and to destroy the “wicked”. How in the world does any of this have to do with the destruction of the Temple in 70 CE? It’s specifically about the coming “Kingdom of God.” This directly aligns with what we already know about Apocalyptic Judaism. All these verses talk about the Son of Man appearing in the clouds with power and glory to bring about a new age on earth. How do you propose to explain that all of this is actually about the destruction of the Temple? It makes little sense prophetically or historically.
You say: I do agree that in that passage (1 Thess 4), Paul is talking about the physical return of Jesus, not the fall of Jerusalem. But if he "believed" it would happen within his lifetime, it was a personal belief on his part. He did not know when Jesus would return, and he did not know when he would die, so he couldn't have thought that Jesus' return within his lifetime was a certainty. He even says in 1 Thess 5:1 that nobody knows when it will happen, and then goes on in 1 Thess 5:10 to say that it might happen after he is gone.
Problem: How can you view Paul’s account of Jesus return as somehow “separate” from what Jesus prophesied in the Gospels so many times? In both accounts, Jesus/Son of Man comes as a thief (Luke 17:30-35) and the Elect are gathered to meet him in the clouds (Mark 13:27). This Son of man and coming Kingdom of God will happen within that generation (Mark 9:1, Mark 13:24-27, 30). Jesus even told the high priest during his trial that he’d personally see the Son of man coming in the clouds with God (Mark 14:62). This is the event Jesus was preaching about in every single apocalyptic prophecy: what reason do you have to interpret it as the fall of the Temple? You’ve given me no scriptural evidence to justify your claims that it’s about the temple, while I’ve given plenty to support the notion that it’s about the Return of Jesus as the son of Man. For claiming that I’m the one with a conspiracy theory you’ve given little to no scriptural justification or explanation for your own interpretations.
You say: Nope. If you want to come up with alternate theories that disregard large chunks of evidence, feel free. But don't make it sound like I'm the one proposing them. The Gospel Paul preached is the Gospel that Luke recorded, and it's not significantly different than the others.
Problem: Why do you consider the entire NT “evidence”? Evidence for what, to prove what? Do you even think these are biographies with different themes or letters with different purposes? You’re completely rejecting the historical method and instead, your only motivation is to harmonize every NT book with every other NT book, since you view them all as “evidence.” Thus, if I dispute a single thing the Bible says, you can claim that I’m “disregarding evidence.” This is ridiculous. Instead of viewing the entire Bible as “reliable evidence” you should divide it up as “strong evidence” or “weak evidence.” Evidence which doesn’t pass historical accuracy is weak. Evidence written later from the events is weak. Evidence not found in multiple sources is weak. Evidence that directly supports the author’s bias in a hotly debated subject is weak.
Imagine if a courtroom judge or lawyer used your method instead of mine. You’d get 5 proclaimed witnesses of the same event, each with different stories. Your method attempts to ignore the human factor by claiming all witnesses are reliable, you skip interrogation, and instead harmonize all 5 accounts into a single event. My method attempts to remove the human factor by claiming all witnesses are not reliable, and uses only information that passes interrogation methods (critical-historical method), and combines that information into what we can reliably say about the event. Which method do you think a courtroom uses to deal with witnesses?
You say: And if they treated all documents the same as you treat the NT ones, starting with the assumption that anything which *doesn't* cut against the grain must be *false*, we'd be disregarding much of almost all historical documents. Most of what is in historical documents is consistent with those documents, so we don't only accept those few pieces which are inconsistent with the documents.
Problem: Incorrect. The “cutting against the grain” technique works best when there’s only one sociological source for our information, because it’s main purpose is to remove bias in a hotly contested subject. In the case of the NT, they are all proto-orthodox Christian sources, so cutting against the grain is extremely useful. I also never said that “anything which *doesn’t* cut against the grain must be *false*”
When an idea cuts against the grain, is supported in multiple, independent, early source, and supports cultural context, then it should be strongly considered. Just “cutting against the grain” by itself isn’t good enough. Interpreting Jesus as an apocalyptic prophet is found in multiple, independent, early sources, it supports cultural context, and it cuts agains the grain. Stop making sweeping, inaccurate accusations to discredit a well established, highly logical method of interpretation.
You say: And then you're adding in "assume right off the bat that a lot of it is wrong", which is *not* used for every historical document ever written. If you were to apply those 4 criteria to, say, Thucydides' accounts of the Peloponnesian War, you'd have to declare it false, as well. We have a single source, Thucydides, and it doesn't cut against the grain in most matters, and contextual accuracy doesn't really enter into the issue for most matters. Since we have multiple, independent sources for the Gospels, they are, per this method, automatically better evidenced than the entire Peloponnesian War. For many historical events, we have only single sources.
Problem: Once again you grossly exaggerate and simplify the historical-critical method, choosing to focus only upon it’s notion of “cutting against the grain.” Do we have multiple, independent sources for the Peloponnesian War? No, so we can’t do a comparative analysis with other texts. Also, Thucydides was writing about an event he didn’t participate in and had no sides to take in. This greatly limits the application of “cutting against the grain” since this method is most successful when there are multiple sources coming from the same sociological background The purpose of the method isn’t to discredit a single-source account, the purpose of the method is to figure out which stories we can be cetain weren’t fabricated through bias. In the case of the Bible, we have multiple independent source (Mark, Q, M, L) coming from the same sociological background (Christians) so cutting against the grain in context of these four sources will produce the most historically accurate, and historically likely account. The fact that cutting against the grain also strongly correlates with what we already know about the cultural context of Apocalytic Judaism increases the merits of that method, and the results of that method.
You say: There's no way around the fact that you're personally holding the NT documents to a different standard.
Problem: It’s true that, relative to single-source historical account, the NT documents are held to a higher standard. But this is precisely because we are able to do so, thanks to multiple independent sources of the same exact story. If only one person saw a murder, you’d have to take their word for the most part. If four or five people saw a murder, you could hold them to a higher level of interrogation simply because there is more information to be compared and contrasted.
You say: A reasonable alternative to rejecting whatever evidence doesn't fit with your theory? Yes, I do have a reasonable alternative - looking at *all* of the evidence and going where the preponderance of the evidence points.
Problem: You not only look at all evidence, you accept all evidence as likely true and attempt to harmonize it together to support itself, despite it coming from various communities with different motivations and purposes for writing. You don’t realize it, but you’re making the mistake of quantity over quality. You claim that since Jesus' resurrection is supported by the most evidence (NT/early Christians) it must be true. You should instead be looking at evidence from a qualitative perspective, especially considering that every drop of evidence you have comes from the same exact sociological source with a strong theological agenda; proto-orthodox Christians. Which evidence is better than other evidence? To determine this, we use the critical-historical method to great success. Apocalyptic Jesus is supported through multiple, independent early sources, through known cultural contexts, and through cutting against the grain. Divine Jesus is supported by multiple independent sources, but not early sources, not the cultural context, and not cutting against the grain. Thus historical Jesus fits much better with interrogation methods than Divine Jesus. Instead of asking yourself which side has more evidence, you should be asking yourself which side has better evidence?
You say: How do you figure that? If a church father says, for example, that Matthew wrote the Gospel of Matthew, I don't consider that "proof" that Matthew wrote Matthew, but I certainly do consider it "evidence", and, in the end, I go where the preponderance of the evidence points. If there is evidence that the author *didn't* write the Gospel which bears his name, then I weigh that in as well.
Like I said, I understand your refusal to accept any claim that involved miracles, but Matthew writing Matthew (and Luke writing Luke, etc.) doesn't involve miracles. At best, you can say that the evidence doesn't constitute 100% undeniable proof, which I'll agree with. They could have been wrong. But I see no convincing evidence that they were. If you have any evidence that they were wrong, feel free to share it.
Problem: The problem is that when you look at the Gospel of Matthew, you do so within the context of what the church father has already said. You don’t look at the internal evidence separately from external evidence. You specifically interpret the internal evidence to support the external evidence. Also as I demonstrated, even Christian universities accept that Matthew has no discernable connection to the Gospel. You are once again on the fringe of belief concerning Matthew.
You say: From what you're saying, it sounds like you consider the method where you reject whatever evidence doesn't fit with your theory to be the one that has more intellectual integrity and honesty. Personally, I think the approach where I weigh the evidence and go where the preponderance of the evidence points to have more intellectual integrity and honesty.
Problem: You ignore all human elements within the NT and claim it’s all true and all accurate in some way until proven otherwise. The historical method, on the other, removes the human elements from the “evidence” to figure out which claims we can be certain of, which claims are of higher quality. The evidence that doesn't fit the historical method is evidence that is not found within early, multiple independent sources. It is evidence that is not culturally in context. It is evidence that could very likely have possible bias from the author. Traditional beliefs on Jesus are all victim to these violations of quality, and do not pass interrogation. You are refusing to distinguish good evidence from bad evidence because you reject the notion that there could be such a thing found within a single Gospel. Your rejection is a tremendous and unfounded assumption, ignoring the proven fact that Mark/Q/M/L are our earliest sources and different tremendously from later documents like John.
You say: I agree. And the main difference is that you reject any explanation involving the possibility of miracles outright, and I don't. But you take it a step further than that, assuming that pretty much anything the church fathers said about Jesus is false, unless you see it as inconsistent with Christianity. You take the "cutting against the grain" bit too far, assuming that "if it cuts against the grain, it must be true" must also mean "if it doesn't cut against the grain, it must be false", which is a logical fallacy on your part and not something other historians would agree with. And I don't know if you do this or not, but I've seen some skeptics say that if only *one* Gospel source reports a detail (such as a quote), but the other sources don't report that same detail, then the detail is probably false. "Multiple attestation suggests truth" doesn't mean "single attestation suggests untruth". An author reporting something as true doesn't suggest it isn't true.
Problem: Once again, you simplify the entire method into “cutting against the grain” when the success of that method hinges much upon multiple, independent early sources coming from a single sociological foundation (Christianity). You say that a single source for a story doesn’t suggest it’s false. But when that single story contradicts or disagrees with earlier, independent stories it becomes less likely. When that single story also disagrees with cultural context, while the early independent stories agree with cultural context, then that single story is even more on the fringe of “truth.”
JOHN VS SYNOPTICS
You say: They both agreed that Jesus was both man and God. Of course, if you ignore some passages from each author, you can make an argument to the contrary. See Matthew 1:23 (confirming Jesus as God) and John 1:14 (confirming Jesus as man), for example. I do agree that much is difference between the various Gospels, which is exactly what we'd expect from different sources for the same series of events. But the differences aren't enough to prove that one author or the other was lying about what they wrote, just that they had different perspectives. Matthew was writing for a Jewish audience, hoping to convince them that Jesus was the promised Messiah, while John was writing for an audience of Christians and gentiles.
Problem: You say that “much difference” should be expected between John and Matthew, but then claim that Mark’s Gospel and Matt’s Hebrew Gospel were just so darn similar that Matt decided to use Mark out of laziness! This is complete contradiction on your end, showing that you change your story to fit your need instead of basing your ideas on any kind of objective, well researched criteria.
In any case, Matthew 1:23 does not confirm Jesus as God, and nothing in Mark/Matt/Luke confirms Jesus as God. All of these authors were perfectly content to view Jesus as a vessel being used by God, just like every other Messiah. Luke especially draws attention to how Jesus is the new Moses. Your interpretation is once again taking a Jewish teaching and placing it in the context of later-evolved Christianity. The phrase “God is with us” fits just fine within the Jewish concept of Messiah and Jewish concept of “son of God” – Jesus was a vessel used by God to demonstrate his power, just like Moses and Elijah and other Messiahs. The verse is actually a reference to Isaiah 7, and Jewish tradition had no reason to interpret that passage as being about a Messiah – it’s about a boy who is born and who does nothing else, really – the boy is simply a sign for other coming events of God, like two countries being “laid to waste,” and the “King of Assyria” decending upon the house of David to cause destruction. This all happens “before the boy knows enough to reject wrong from right.” Then the boy is never mentioned again. This makes no sense in context of the story of Jesus, it was simply Matthew grasping at straws to prove that Jesus was actually fortold in the OT, to give his Messiahship more credit. This is why the vast majority of Jews rejected these stories of Jesus: Matthew/Mark/Luke were grabbing at random OT straws to prove the jewish “Messiahship” of Jesus, but Jews knew they were twisting and mixing up OT scripture in order to do so. Not a single passage in the OT which specifically talks about a “Messiah” also talks about a virgin birth, or a suffering, or Resurrection, or anything else Jesus related. How can Christians claim that Jesus was a Jewish Messiah when not a single OT passage using the word “Messiah” confirms any events from Jesus’ life?
On to John.
I've already vaguely mentioned the difference between John and the other Synoptic Gospels. What is striking is how both the content and emphasis of Jesus words and deeds is so different. I claimed this is grounds to prove it wasn't written by a disciple. You, on the other hand, originally claimed that 1) The only substantial difference between John and the Synoptics is explanable due to the "destruction of the Temple" prophecies and 2) John, even if he didn't write it himself, could give oral dictation to someone. I will document how both of your claims are not supported by the evidence.
1) You claimed that there's no major differences between John and the Synoptics.
I will list some of the major provable differences here:
In the Synoptics, Jesus refuses to give signs in order to prove his identity. The miracles he performs are only to show that the Kingdom of God is coming and to help those in need, not to prove a self-identity. However in John, Jesus uses signs precisely in order to prove his identity, and says nothing about the Kingdom of God. Examples of this contrast:
Then some of the Pharisees and teachers of the law said to him, "Teacher, we want to see a miraculous sign from you." He answered, "A wicked and adulterous generation asks for a miraculous sign! But none will be given it except the sign of the prophet Jonah. Matthew 12:38-39
"Unless you people see miraculous signs and wonders," Jesus told him, "you will never believe." John 4:48
To illustrate this further, Jesus delays helping a sick man in John in order to let the sick man die first. That way, Jesus can prove his identity through resurrecting him:
When he heard this, Jesus said, "This sickness will not end in death. No, it is for God's glory so that God's Son may be glorified through it." ...when he heard that Lazarus was sick, he stayed where he was two more days." John 11:4-6
Jesus then proceeds to perform a very public resurrection of Lazarus after he dies from the sickness. Compare this to the resurrection story found in Mark of the young girl. Jesus is delayed inadvertently on his way to her, he does not do it on purpose. He heals the girl in private, talking only with her parents and a few disciples. In John, Jesus makes the healing a public spectacle, with crowds looking on. This demonstrates a very strong difference thematically between the Synoptics and John, which fundamentally changes the character of Jesus. In the Synoptics, Jesus is tempted by Satan to do a miracle to prove his identity, the second temptation of being caught by angels when he leaps from the temple. John omits the temptation stories and omits Jesus' refusal to give signs (Matt 12:39) from his account for obvious reasons. They directly conflict with his views on the purpose and nature of Jesus’ life.
Another marked difference is how each portrays Jesus' teachings. In the Synoptics, Jesus spends almost his entire ministry speaking in parables and talking about the imminent arrival of the Kingdom of God (Mark 14:62) and how to prepare for it. Compare this to John. Jesus gives not a single parable. He spends almost his entire ministry teaching about himself: how he pre-existed, how his message alone can bring eternal life, how he himself is the only way to God. His miracles are how he proves his identity: he multiplies loaves of bread while claiming to be the "bread of life." He gives sight to the blind and says that he is the "light of the world." He calls himself "the resurrection and the life" so he raises people from the dead.
The author of this Gospel is writing a biography, just as the Synoptics, but both of them certainly can't be correct when viewed historically. There are too many contradictions and mixed messages to be found, and they are two very different portrayals of Jesus' character and what he spent his life doing. Each author was inserting their own thematic message into their story of Jesus, while shaping the content around that theme. The theme was learned either through oral and written traditions that passed on to that particularly community. John's community had a much different view of Jesus' life than the Synoptic community.
2) You claim John either wrote this Gospel himself or had someone write down his account for him.
As we can see, John's account differs vastly from the Synoptics. This is internal evidence against disciple authorship. More importantly, there are clues that tell us that the author of John was the same kind of author as Matthew and Luke: a compiler of various stories. There is internal evidence that shows that multiple sources were being used, not a single "disciple" source as you claim.
Internal evidence #1: Difference in Writing Style. The introduction to John is vastly different than the Synptics as well as other Greco-roman biographies. The main theme of the prologue typically sets out the theme for the entire biography: this happens in Mark, Luke and Matthew, each in their own unique way. It happens in other Greco-roman biographies. But it does not happen in John. Instead we get a sort of hymnal in praise of Jesus, poetry perhaps, which has a specific main theme that doesn't repeat in the text: Jesus is the "Word made Flesh." This suggests that the hymnal was an independent source.
Internal evidence #2: Repetitions. There are several accounts in John that appear redundant, where similar accounts are repeated in slightly different words. These passages may derive from different sources. For example, chapters 14 and 16 are remarkably alike in their key themes, and could be summarized in almost the exact same way. It may have been repeated for emphasis, but the repetitions seems less emphatic than simply redundant. Another explanation is that there were two sources for the same account. This becomes especially evident when when we look at the third kind of internal evidence.
Internal evidence #3: Literary Seams. Authors who compose their books by splicing several sources together don't always neatly cover their tracks. Some examples:
--Jesus performs his "first sign" in 2:11 and performs his "second sign" in 4:54. However, in 2:23, between the the first and second sign, Jesus converted many people "because they saw the signs that he was doing." How can he do the "first sign", and then other "signs", and then the "second sign"? It wouldn't have been the second one - so why this strange mistake?
-- In 2:23 Jesus is in Jerusalem, the capital of Judea. He talks with Nicodemus until 3:21. Then the text says "After this Jesus and his disciples went into the land of Judea" (3:22). But they are already in the land of Judea, and in fact it's capital. Another strange mistake that one wouldn't expect if the narrative was consistently told through one source.
--In 5:1 Jesus goes to Jerusalem to heal and teach. After this discourse, it says "Jesus went to the other side of the Sea of Galilee" (6:1). How could he go to the other side of the sea if he is not already on one of its sides? In fact, he is nowhere near the Sea of Galilee; he is in Jerusalem of Judea, about 60-70 miles away.
-- In 13:36, during the last supper, Peter asks Jesus where he's going. Some verses later, Thomas asks the same question(14:5). Oddly, several minutes later Jesus states "But now I am going to him who sent me; yet none of you ask me, 'Where are you going?" (16:5). Why the memory laps in conversation? It makes no sense historically or narratively if this were supposedly based off a single source.
--A the the end of Chapter 14 after delivering a speech of near a chapter and a half long, Jesus says to his disciples "Rise, let us be on our way" (14:31). Instead of getting up and leaving, however, Jesus launches into another discourse that lasts all the way into chapter 17. They do not leave until 18:1. Why would Jesus say "Rise, let us go," and then not leave for three more chapters of dialogue?
So what is the easiest way to solve these internal errors? For the "signs" mistake, it's easy to hypothesize that there was originally a "signs" source: a writing that detailed 7 specific, divine signs of Jesus, since there are seven specific signs within John (not counting chapter 21, which very likely could've been added). The author decided to incorporated this "7 miracles of Jesus" source into the Gospel. There is other evidence that this was a self-contained source: after the final sign of raising Lazarus in chapter 20, the text seems to imply it's the end of the story:
Jesus did many other miraculous signs in the presence of his disciples, which are not recorded in this book. But these are written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name. John 20:30-31
Of course, John continues on into chapter 21, in which Jesus does some more signs, but that makes little literary sense in light of the above verse. And there's an early version of John that omits chapter 21, implying that this particular chapter could very well be a later addition to the original Gospel.
As for the inconsistencies in dialogue between chapters 13-18, we can eliminate them if we simply say the author of this Gospel combined two written sources of the same event. Source A consisted of chapters 13/14/18 and Source B consisted of chapters 15/16/17. The author simply inserted Source B in the middle of source A to combine them together into a single narrative. It is a simple solution, which solves not only the redundant content but also the conversational errors by Jesus.
There are also other possible sources that John used. There are strong similarities between the passion narrative of John and the Synoptics, implying he might have used a source similar to them for that particular story. And as I said earlier, there was likely a separate source for the introductory poem to John, either an oral or written.