When we read the gospels, its clear that Jesus believed in hell. In fact, Jesus had a lot to say about it. If Jesus is in fact the Son of God, then clearly His words on this matter should be taken seriously. For those who are not Christians and choose not to trust Jesus for your salvation, I think it's still important to understand what the Bible teaches so you understand the risk of rejecting Him. The passage below shows Jesus being much more direct about what happens to us after this life.

"“When the Son of Man comes in His glory, and all the holy] angels with Him, then He will sit on the throne of His glory. All the nations will be gathered before Him, and He will separate them one from another, as a shepherd divides his sheep from the goats. And He will set the sheep on His right hand, but the goats on the left... Then He will also say to those on the left hand, ‘Depart from Me, you cursed, into the everlasting fire prepared for the devil and his angels ... And these will go away into everlasting punishment , but the righteous into eternal life." (Matthew 25:31-33, 41 ,46) NKJV

I've heard some Biblical scholars say that, at the end of this life, those who aren't saved simply cease to exist. In other words, there really isn't anything to fear for those who reject Jesus Christ. Jesus certainly did not teach that. In fact, a significant amount of Jesus' teaching was wrapped around a warning. From the beginning of His ministry, He repeatedly preached the need for repentance "for the Kingdom of Heaven is at hand." This implied that there were consequences for choosing not to repent. Eventually, Jesus began to be more clear about the nature of the consequences.

"But I say to you that whoever is angry with his brother without a cause shall be in danger of the judgment. And whoever says to his brother, ‘Raca!’ shall be in danger of the council. But whoever says, ‘You fool!’ shall be in danger of hell fire. " (Matthew 5:22) NKJV

The passage below is even more clear that hell is a real destination to be feared.

"If your hand causes you to sin, cut it off. It is better for you to enter into life maimed, rather than having two hands, to go to hell, into the fire that shall never be quenched—where ‘Their worm does not die and the fire is not quenched.’" (Mark 9:43-44) NKJV

Consider for a moment how bad hell would have to be that it would be better to cut off your own hand than to end up there. This is incredibly strong speech. I can't really claim to know for sure what "their worm does not die" means, but it sure sounds bad. I believe what he's saying is that this fire does not consume. And, it never stops or dies down. It simply torments endlessly. And finally, Jesus gave another parable related to hell about a rich man who refused to help a beggar in need.

"There was a certain rich man who was clothed in purple and fine linen and fared sumptuously every day. But there was a certain beggar named Lazarus, full of sores, who was laid at his gate, desiring to be fed with the crumbs which fell from the rich man’s table. Moreover the dogs came and licked his sores. So it was that the beggar died, and was carried by the angels to Abraham’s bosom. The rich man also died and was buried. And being in torments in Hades, he lifted up his eyes and saw Abraham afar off, and Lazarus in his bosom.

Then he cried and said, ‘Father Abraham, have mercy on me, and send Lazarus that he may dip the tip of his finger in water and cool my tongue; for I am tormented in this flame.’ But Abraham said, ‘Son, remember that in your lifetime you received your good things, and likewise Lazarus evil things; but now he is comforted and you are tormented. And besides all this, between us and you there is a great gulf fixed, so that those who want to pass from here to you cannot, nor can those from there pass to us.’" (Luke 16:19-26) NKJV

This passage might be described as simply an allegory rather than a description of hell, except that it's clear from the previous passages discussed that Jesus clearly believed that hell was in fact a real place. This was not something he made up to prove a point. This is something he is warning us against in as many ways as He can.