Exodus 29:18 And thou shalt burn the whole ram upon the altar: it is a burnt offering unto the LORD: it is a sweet savour, an offering made by fire unto the LORD. (KJV)
Exodus 29:36 And thou shalt offer every day a bullock for a sin offering for atonement: and thou shalt cleanse the altar, when thou hast made an atonement for it, and thou shalt anoint it, to sanctify it. (KJV)
Leviticus 1:9 But his inwards and his legs shall he wash in water: and the priest shall burn all on the altar, to be a burnt sacrifice, an offering made by fire, of a sweet savour unto the LORD. (KJV)
Leviticus 23:27 Also on the tenth day of this seventh month there shall be a day of atonement: it shall be an holy convocation unto you; and ye shall afflict your souls, and offer an offering made by fire unto the LORD. (KJV)
Psalms 50:13 Will I eat the flesh of bulls, or drink the blood of goats? (KJV)
Isaiah 1:11 To what purpose is the multitude of your sacrifices unto me? saith the LORD: I am full of the burnt offerings of rams, and the fat of fed beasts; and I delight not in the blood of bullocks, or of lambs, or of he goats. (KJV)
Jeremiah 6:20 To what purpose cometh there to me incense from Sheba, and the sweet cane from a far country? your burnt offerings are not acceptable, nor your sacrifices sweet unto me. (KJV)
God approved of sacrifices, as long as there was repentence of the sins to accompany them. He prefers for people to not sin in the first place, as opposed to willingly sinning and then offering a sacrifice, thinking everything is okay. In the Psalms, Isaiah and Jeremiah passages, God was speaking of those who continued in their sinful ways without repentence. For these people, sacrifices alone were not acceptable. It should be noted, though, that the sacrifice Jesus made on the cross made further animal sacrifice unnecessary. Not a contradiction.