Why aren't Christians allowed to burn non-believers to death any more? Isn't that a violation of the separation of church and state?

because their cult is getting weaker and weaker. And they are incapable of doing jacksh*t to anyone. Its the same reason that christians arent allowed to be lion food no more

religion back in the past was a form of crowd control, let's face it life was pretty śhitty back in the past with trying to get rid of pagans, invasions of Romans and vikings, medieval wars, the French etc etc. They needed people untied with hope under one flag and what was better than a deity of the promised lands of heaven. They didn't like heresy because it was a form of revolution back then, a stray sheep let's say and to herd them back in they burnt one of them alive, the most painful form of execution imaginable and that way it kept everyone in check.

Yes I thing we should be allowed!

cruel and unusual punishment was done away probably do to Salem witch trials, but though I agree that its wrong to torture and burn people alive, witches are still criminals, and if they worship any deity other than worshipping the One true God and don't repent they are guilty of idolatry
BTW, Christians aren't the only people to burn people, in the book of mormon wicked men of false priestcrafts did it to those american Indians who did believe in Jesus Christ, to women and children and to prophets, So, also, did Jezebel seek to kill all the prophets in Israel but she didn't kill Elijah

Christians are supposed to follow Jesus' example of being merciful and kind, so violence towards other people is best avoided, except to stop a threat (such as war, self-defense, police fighting criminals and terrorists, and execution of the worst criminals such as murderers and terrorists).

In spite of some verses in the Old Testament that command the execution of Pagans and blasphemers, now that Jesus had died for us, we do not have to be extremists anymore.

Furthermore, I do not see being nice to non-believers as "violating the separation of church and state"; it would be a violation if the state or church tries to impose their religion by torturing, killing, or forcing non-believers to convert, like ISIS and many terrorists do.

Most non-believers do not go around committing terrorism, so why do we even have to exterminate them? Doing so is an abomination, as horrific as human sacrifices and cannibalism.

That is just one more example of the never-ending persecution of christians!

Back in my day we used to round up commie atheists and throw them in camps.