Henry VIII sure had no qualms about putting people to bloody deaths yet considered himself a very pious man and representative of God. This after he divorced his wife because he was desirous to marry his girlfriend. He sired children through affairs while married to his first wife.
How did he ever work it out he was so pious?
He wanted to ensure at least one son to succeed him. His training was to become Archbishop of Canturbury, but his elder brother died in his teens, so he wound up religiously educated but the secular ruler. When he was denied an annulment, he took over the English church, being better qualified to lead it than the Medici pope.
Of course, piety and atrocities go hand in hand regardless.