Jesus repeatedly and insistently warns us about hell:
“For wide is the gate and broad is the road that leads to destruction, and many enter through it. But small is the gate and narrow the road that leads to life, and only a few find it.” (Mt 7:13-14)
“If your hand or your foot causes you to stumble, cut it off and throw it away. It is better for you to enter life maimed or crippled than to have two hands or two feet and be thrown into eternal fire.” (Mt 18:8)
“The Son of Man will send out his angels, and they will weed out of his kingdom everything that causes sin and all who do evil. They will throw them into the blazing furnace, where there will be weeping and gnashing of teeth.” (Mt 13:41-42)
Why these terrifying announcements?
If hell is to serve its purpose of being the incentive that no one can fail to heed and correct his ways upon being exposed to it, that is, given that hell exists in order to deter everyone from actually going there, the threat of it must be widely promulgated and publicized to all concerned.
The people must be reminded of it time and time again. The point is not to paralyze folks with fear (though that can be an unhappy side effect), but to ensure that all are in fact saved.
I hope I am not sabotaging Jesus’ stratagem, but regardless of this understanding, it is fully possible to go to (human) hell; it’s just that in actual fact, hell is empty. But there is no limit to the suffering one can undergo before he decides by and for himself to wise up and sin no more.