Avengers are zealot inquisitors. They just find someone their god doesn't like, chase them down and harvest their organs.
Madness string 3256
In biblical days, the way to atone for your sins was the sacrifice on the altar to God. What people don't remember now is that the altar doesn't get cleaned afterwards. So with every sacrifice, the altar gets bloodier and bloodier. It's basically a reminder of every transgression and you can't go back to the unclean state.