This is another post that sat in my drafts for several years, originally intended as a reference for myself ahead of a small group meetup. I never published it because I didn't think I had a good reason to publish it publicly, but again, this is my blog - do I need a good reason to publish anything here? Even so, perhaps these thoughts may help someone else, or perhaps someone will offer a critique that requires me to sharpen my own views. Either one would be good.
The punishment vs. the crime
Implicit in this question is, I think, the idea that the punishment does not fit the crime. If I were to steal $20 from someone, and my punishment was death by firing squad, we would say that this is unjust. Why? Because the punishment clearly does not fit the crime. I think this is the same problem raised by someone who asks "How can a good god send people to Hell?"; they believe Hell is a punishment that does not fit the crime of sin.
Put another way: surely the finite sins we commit do not deserve the infinite punishment that is Hell.
Maybe the punishment does fit the crime
The sins we commit are not finite. If I murder somebody, this is not only a transgression against the person I murdered, but also against God. A creature existed that God created in His image, who he intended to have life, and I took that creature's life against God's command for such creatures ("thou shall not murder"). All sin, though varying in severity, is committed against God.
Why does this make a difference? Here's a comparison:
If I key my neighbor's car, there are consequences. I have to pay to fix it, and maybe my neighbor and I are not on good terms anymore. If I key a car at a local used car lot, the consequences are a little more severe. I'll probably have to pay more money, and I may be barred from buying from them, and perhaps I will have something added to my criminal record. If I key a car at a Ferrari dealership, you can imagine the consequences - I'd have have to go into debt to pay that one off and would definitely have a criminal record. Now, imagine there is a one-of-a-kind car, whose designer and builder are no longer alive, and nothing like it will ever be created again - and I key it.
God's value is infinite. His majesty is infinite. As finite creatures we cannot possibly repay the damage done when we sin against an infinite being. Unless this is rectified, we will experience eternal separation from God - what we call "Hell".
And yet, there is an escape
Even though Hell is a punishment that does fit the crime, we are still offered an escape. God, who is also good, loving, and merciful, created a plan to save us: salvation through faith in Jesus.
This means that those who end up in Hell not only sin against God, but also reject His offer of reconciliation, and so ultimately choose that destination themselves.