1) Hell is not a place of physical torture. The "flames" are clearly metaphorical. If it were literal, then wouldn't we assume that hell being described as an "outer darkness" must also be taken literally? If so, wouldn't the flames light up the darkness? Also, our physical selves die in this world, so how could we experience physical ANYTHING in the afterlife?

2) Jesus didn't come to send non-believers to hell, but to save believers from hell. If you were drowning and someone threw you a life preserver saying "grab onto it or drown," would you consider that person as threatening to drown you? A promise of salvation (what Jesus offered) is the polar opposite of a threat of damnation.

So what is hell? Hell is the eternal absence of God. It's perishing. John 3:16 (perhaps the most quoted verse from the Bible) says "For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life." Only non-believers could twist that into a threatening thing.