"Christians who support the death penalty often cite passages from the Old Testament that allowed for capital punishment. But Jesus told his followers not to observe the Jewish law that allowed for retributive justice:
"You have heard that it was said, Eye for eye, and tooth for tooth.' But I tell you, do not resist an evil person. If anyone slaps you on the right cheek, turn to them the other cheek also."
As theologian Benjamin Corey says, "It is not possible to argue a Christian case in support of the death penalty while citing passages from the Hebrew scriptures, because this will put one at odds with Jesus himself."
I have a feeling that the executed first-century teacher would not support the death penalty or want his followers to.
Many forget that Jesus once served as a one-man jury on a death-penalty case.
In a famous New Testament story, an adulterous woman was dragged to Jesus' feet. The woman was guilty of a capital offense and had been caught in the act by at least one witness. The law mandated her death but Jesus prescribed a different response:
"Let whoever is without sin cast the first stone." He was teaching that only a perfect being -- only God -- should have power over death and life.
With Jesus's stark words and example, no wonder early Christians opposed military service and the government-sanctioned killing of anyone for at least 300 years. "Our warfare is to make the dead to live, not to make the living dead," St. John Chrysostom said."
much more at the article.
WWJD? questions are not my favorites because, according to Christian belief, we ain't Jesus; not much perfect about us.
I've opposed the death penalty except for what I think of as heinous crimes such as those against children, but were I perfect spiritually, which I will never be on this earth, I would not make such allowances.