There is a saying in this world "if you can't do the time, don't do the crime". The obvious implications are that those who suffer punishment are suffering justly. They had a choice to do the right thing (or at least not do the wrong thing), but they chose to do the wrong thing. The natural result of this is some form of punishment.
And indeed, such punishments exist. In the UK alone, there are 117 prisons specifically designed to punish those who commit certain crimes. But by this point, telling them "don't do the crime" is a little too late. You need to get to them before they do the crime. The problem is, for most of them, you already have. How many criminals will commit their crime knowing they're in full view of a police officer? They knew their crime was illegal, they just very likely did not expect the result. Whether they thought they wouldn't get caught, or that they wouldn't get punished, they thought their crimes were worth it.
The physical world closely mirrors the spiritual world. Just as there are laws of the land, there are also laws of the Lamb. When these laws are broken, it's called sin. That is, an offense against the infinite and eternal God. The problem is, it's useless telling us "if you can't do the time, don't do the crime", because every single one of us has sinned. This can be proven just by going through the most well known laws: The 10 commandments. Most of us have lied, stolen, dishonored our parents, committed adultery (which, in Matthew 5:21, Jesus says includes looking upon a woman with lust), held other things in higher esteem than God (whose name we have taken in vain). Scripture even says that hatred is equivalent to murder (1 John 3:15). We, as a species, are wicked.
So what must a Holy God do with us? This depends who you ask. A liberal "Christian" might say that since God loves us, He'll be ok with our sin, either because it's something we like so He won't call it sin after all, or because we're generally good people, so He can overlook the bad. But of course, even sinners know the flaw with this when sin is committed against them. "I'm generally a good person, so it's ok for me to steal your wallet". God is perfect and Holy, therefore He must deal with sin. He can't just let it go. That's imperfect.
Of course, if you ask an atheist or an unbeliever, they'll say God can't do anything at all. If God doesn't exist, He can't judge you, can He? But this fails for two reasons. First, if God didn't exist, neither could morality. Moral laws require a moral law giver. Just as you cannot say "this is illegal" if there is no government, you cannot say "this is evil" if there is no God. But our governments cannot all agree on right and wrong, with some of them even doing what others of them think is wrong. Is morality really just an endless war, with the one who is right being the one with the biggest gun? Even most atheists are willing to admit that Hitler, for example, was evil, but a wise atheist will admit that, without God, all they can really do is say it's a personal disagreement with him.
But more than that, the fact is atheism is a temporary delusion. At the end of it all, it is appointed for a man once to die, and then face judgement (Hebrews 9:27). Every atheist, whether they like it or not, will one day die, and face the God they so flippantly dismissed. And He will dismiss them in kind, straight into the eternal fire where no one wants to go.
Of course, it's not just atheists. The aforementioned liberals, the Relativists, everyone who believes they will be spared God's judgments, will nevertheless be brought before Him to face them. One thing, and one thing only, can spare we who have done the crimes from doing the unbearable time: The blood of Jesus Christ.
With God, justice is not an option. It is a vital part of His character; He cannot allow sin to go unpunished. But who, exactly, takes the punishment is open for dispute. The fairest solution would be for the sinner themselves to take it. And indeed, unfortunately, this is the option many people will choose. But I am hoping no one who reads this article will be so stubborn, because the second option is far more glorious. 2,000 years ago, Jesus came to live a perfect life as a man. With no sins of His own, He was condemned to die in the manner of a sinner. This allows God to swap our verdicts. The innocent Jesus was condemned as a guilty man. We, therefore, though guilty, can be judged as innocent.