Christians celebrate rape, torture, slavery and genocide.

[John V]

They do have the ability to appeal harsh, unfair or illegal sentences handed down by courts. Judges make decisions based on the law, but they are not above it.

Correct. They don't get to judge the judge themselves, at least not in any effective sense. They can appeal to other judges, i.e. the peers of the judge.

So, if you don't like God's judgment, appeal to his peers.