Some Christians say they are opposed to death penalty because they are Christians. There is nothing is Christianity that is against death penalty. Jesus did not preach against death penalty. Throughout centuries many persons were burnt at stakes for heresy. The church declared crusades.
Jesus spoke of forgiveness. He spoke of showing the other cheek when one is struck on one cheek. But he did not show the other cheek when he was struck during the trial by Jewish leaders. He said “If I have said something wrong, show me where I am wrong. If I am right, why do you strike me?”
At the temple Jesus got angry and whipped the merchants. He did not reply when asked what authority he had to do it. He asked a counter question.
Jesus spoke of casting millstones around the necks of people who cause little ones to sin and throwing them into the sea.
Let not opposition to death penalty be linked to Christianity.