Argument: The death penalty is about punishment/due desert, not vengeance
David Gelernter. "What do Murderers Deserve?". Commentary Magazine. March/April 1999 - "Opponents of capital punishment describe it as a surrender to emotions--to grief, rage, fear, blood lust. For most supporters of the death penalty, this is false. Even when we resolve in principle to go ahead, we have to steel ourselves. Many of us would find it hard to kill a dog, much less a man. Endorsing capital punishment means not that we yield to our emotions but that we overcome them. If we favor executing murderers, it is not because we want to but because, however much we do not want to, we consider ourselves obliged to."
Thomas R. Eddlem. "Ten anti-death penalty fallacies". The New American. 3 June 2002 - "FALLACY #9: Christian Forgiveness and Vengeance
"The death penalty appears to oppose the spirit of the Gospel. In the Sermon on the Mount, Jesus urges us to replace the old law of 'an eye for an eye, a tooth for a tooth' with an attitude of charity, even toward those who would commit evil against us (Mw 5:38-48). When asked for his opinion in the case of the woman convicted of adultery, a crime that carried the penalty of death, he immediately pardoned the offender, while deploring the action, the sin (Jn 8). It is difficult for us to accommodate Jesus' injunction to forgive and love, to reconcile and heal, with the practices of executing criminals." (Statement on Capital Punishment by the Christian Council of Delaware and Maryland's Eastern Shore)
"In Leviticus, the Lord Commanded 'You shall not take vengeance or bear any grudge against the sons of your own people.' Here the Old Testament anticipated Jesus 'teaching: 'You have heard it said, "an eye for an eye and a tooth for a tooth." But I say to you, do not resist one who is evil. But if anyone strikes you on the right cheek, turn to him the other one also.' Paul likewise proclaimed that vengeance is reserved for God and that Christians should feed their enemies, overcoming evil with good (Rom 12:19-2 1)." (Christianity Today 4-6-98)
Correction: Punishment -- sometimes called retribution -- is the main reason for imposing the death penalty. The so-called 'Christian' case against the death penalty can be summed up in one sentence: We cannot punish wrongdoers because punishment is always a form of vengeance.
A careful reading of the Bible does not back up the idea that punishment is synonymous with vengeance. The proportionate retribution required by the Old Testament generally replaced disproportionate vengeance. The same Old Testament that ordered "an eye for an eye and a tooth for a tooth" also prohibited vengeance. Evidently, the Hebrew scriptures view retribution and vengeance as two separate things. In the New Testament, Jesus denied trying to overturn the Old Testament law. "Do not imagine that I have come to abolish the Law or the Prophets. I have come not to abolish them, but to complete them." (Matthew 5:17) The apostle Paul told the Romans that revenge and retribution are different things entirely. "Never try to get revenge: leave that, my dear friends, to the retribution. As Scripture says, vengeance is mine -- I will pay them back, the Lord promises." But then just a few verses later, Paul notes that "if you do wrong, then you may well be afraid; because it is not for nothing that the symbol of autho rity is the sword: it is there to serve God, too, as his avenger, to bring retribution to wrongdoers." (Romans 13:4) "Authority" refers to the state, which is empowered to put evildoers to the "sword." Paul asserts that the state's retribution of capital punishment is the retribution of God.
Clearly, the Christian Testament. regards retribution by the state as not only different from vengeance, but rather as opposites. Vengeance is always personal and it is only rarely proportional to the offense. The Hebrew standard of justice for "an eye for an eye" replaced the hateful and very personal "head for an eye" standard of vengeance. Retribution is impersonal punishment by the state. And impersonal punishment is far more likely to be proportionate to the crime, meaning that it comes closer to the standard of "eye for an eye."
By forgiving the adulterous woman, Jesus was not making a statement against the death penalty. Jesus' enemies thought they had put Christ into a no-win situation by presenting the adulterous woman to him. If Christ ordered the woman's release, they could discredit Him for opposing the Law of Moses. But if He ordered her put to death, then Christ could be handed over to the Roman authorities for the crime of orchestrating a murder. Either way, His opponents figured, they had Him. Christ, of course, knew the hypocritical aims of His enemies had nothing to do with justice. The absence of the man who had committed adultery with the woman "caught in the very act" must have been glaring. His rebuke to "let he who is without sin cast the first stone" was the perfect reply; it highlighted the hypocrisy. Christ's response was in no way a commentary about the death penalty."
Jeff Jacoby, Boston Globe Columnist. "An execution, not a lynching". May 2001 - Bud Welch is wrong to describe capital punishment as nothing but "revenge and hatred" and wrong to imply that revenge and hatred -- as opposed to fairness and justice -- are what drive those who disagree with him. Welch deserves our sympathy for his daughter's death, but he is not entitled to impugn the motives of everyone who supports the death penalty.