But the house of Israel says, 'The Lord's way isn't fair.' Is it My ways that are unfair, house of Israel? Instead, isn't it your ways that are unfair?" - Ezekiel 18:29
People can't decide how God should judge.
Some people think that God just shouldn't judge at all - everybody should be allowed into Heaven no matter what they believe or do in their lives. Al-Qaeda? Heaven. ISIS? Heaven. Greedy corporate executives? Heaven. Corrupt politicians? Heaven. Serial rapists? Heaven. No forgiveness or repentance necessary; they think God should just ignore everything people do anyway.
Some people think that God should judge in a way that's similar to how the legal system judges - that God's judgment should depend on their actions. If people commit "small" sins like lying or something without turning away / repentance (things that generally aren't punishable by human law), they still shouldn't be punished at all for them. They're going against God's clearly-defined and clearly-explained rules, but if they're just "small" things, then God shouldn't judge them at all for it. If people "try", then they should go to Heaven, no matter what. That if
they openly reject God, and continually sin, as long as they don't do
anything that's really really bad (according to their local culture/values) and still give a few dollars to people outside of stores, etc, then God should still let them into Heaven. But if somebody commits a "really bad" sin like murdering an innocent person, etc (things that generally are punishable by human law), then God should send them to Hell by default. It doesn't matter if they genuinely repent, seek forgiveness, do good things later on in their lives ... They maintain that those people should still go to Hell forever.
There are other things as well, but it all boils down to the idea that the way God judges according to the Bible is unfair.
However, the way God judges us is fair. God explains to us what He wants of us in the Bible. Although our society is in a pretty rough spot right now and people disagree on a lot of things, the basic principles remain the same. We need to believe - in God, and in Jesus. We need to accept Jesus as the atoning sacrifice in our lives, our Lord and Savior. And it's not some impossible thing God wants of us here - God has written the law on our hearts, God has created a world that in itself, is evidence of Him, God regularly sends people out into the world to share His word with others. Look - you're reading this post right now. You somehow ended up on an entire blog about Christianity. An entire blog about theology, spirituality, apologetics ... inspired by God. There is tons of proof of His word that can be found with a simple Google search. People who refuse to listen after everything God does, have no excuse. God does punish sin, but in His fairness, understands when a wicked person truly repents, when they truly turn away from what they did. God looks at the situation objectively. God knows what's in their hearts; a human government, or a human legal system, can't look at things as clearly as God does, and so people are just coldly given a prison sentence they have to serve, whether they truly deserve it or not. With God, our sins are forgiven through Jesus. Thus, God does judge fairly. If God sends someone to Hell, He has a very good reason to do so; He doesn't want anybody to die. God is merciful. And on the other hand, God reproves/"punishes"/corrects those He loves - because that's how we, stubborn people that we are, learn. God reproves/corrects us so that we can become better people, learning the ways of righteousness and turning away from sin.
God is fair.
May God bless and guide you all, according to His perfect will. In Jesus name! Amen.