Awesome. Good question really.
Hell is a place without God’s loving rule, which is precisely what people who go there have rejected. As Abi said, because none of us are perfect, none of us deserve to live in God’s perfect world, because “nothing impure will ever enter it” (Revelation 21:27). God is a loving, perfectly just God, and so he judges wrongdoing: mine, yours, everyone’s. Just as it’s fair that a lawbreaker in this country faces punishment, so it’s fair that we who live in God’s world and break his rules face his punishment.

In some ways, since no one is perfect, the real question isn’t: “Why does anyone go to hell?” but: “Why does anyone go to heaven?”

If life were “fair”, we would all go to hell and no one would get to live in heaven, in God’s perfect kingdom beyond Jesus’ return. But the amazing news, as Abi said, is that God has done something to make it possible for imperfect people like us to live in his perfect kingdom beyond death.

And he did it through Jesus, his Son. Jesus will return to this world to judge and punish; but first, he came to this world to serve and to save. He said about himself: “God so loved the world that he sent his one and only Son, that whoever believes in him shall not perish [ie: go to hell] but have eternal life [in God’s kingdom]” (John 3:16).

Jesus made it possible for people to have life with God instead of the hell we deserve by taking the punishment of separation from his Father God’s love and all good things. That’s what he did on the cross, where he cried out: “My God, my God, why have you forsaken me?” (Mark 15:34).

On the cross, Jesus God’s Son was cut off from the love of his Father for the first time in eternity. As he died, Jesus experienced hell. And he did that in our place, so we wouldn’t have to.

The Bible puts it this way: “The punishment that brought us peace was upon him, and by his wounds we are healed” (Isaiah 53:6).

Because of Jesus’ death, hell is now avoidable, rather than inevitable.