There is no place in the New Testament that specifically says that capital punishment is right or wrong. However, there are verses that seem to touch on the subject and support it.  Let’s take a look at them with their context.

• Romans 13:1-4, “Let every person be in subjection to the governing authorities. For there is no authority except from God, and those which exist are established by God. 2 Therefore he who resists authority has opposed the ordinance of God; and they who have opposed will receive condemnation upon themselves. 3 For rulers are not a cause of fear for good behavior, but for evil. Do you want to have no fear of authority? Do what is good, and you will have praise from the same; 4 for it is a minister of God to you for good. But if you do what is evil, be afraid; for it does not bear the sword for nothing; for it is a minister of God, an avenger who brings wrath upon the one who practices evil.”
• Acts 25:10-11, “But Paul said, “I am standing before Caesar’s tribunal, where I ought to be tried. I have done no wrong to the Jews, as you also very well know. 11 “If, then, I am a wrongdoer and have committed anything worthy of death, I do not refuse to die; but if none of those things is true of which these men accuse me, no one can hand me over to them. I appeal to Caesar.”

In regards to Romans 13:1-4, the Christian is clearly taught to be in subjection to the governing authorities. This is a provision for harmony. Though a government may be oppressive, to the preaching of the gospel governments are changed. But, as we look at verse four we see the comment that the governing authority “bear(s) the sword” and that it is “an avenger who brings wrath upon the one who practices evil.”  The question is what is meant by “bear the sword.”  Let’s take a look at some commentaries.

• The sword is a symbol of the power delegated to governing authorities to enforce acceptable social conduct. Here we have the biblical basis for the use of force by government for the maintenance of law and order. The power to punish has been delegated by God to those who rule.[fn]Robert H. Mounce, vol. 27, Romans (electronic ed.;, Logos Library System; The New American Commentary Nashville: Broadman & Holman Publishers, 2001, c1995), 244.[/fn]
• “(though “the sword” might possibly be understood as only the familiar symbol of power, yet the mention of it may be taken to imply the apostle’s recognition of the legitimacy of capital punishment, such as he also expressed distinctly,”[fn] The Pulpit Commentary: Romans ( ed. H. D. M. Spence-Jones; Bellingham, WA: Logos Research Systems, Inc., 2004), 390.
• “Keep in mind that God ordained human government, including capital punishment,”[fn] Warren W. Wiersbe, Wiersbe’s Expository Outlines on the New Testament (Wheaton, Ill.: Victor Books, 1997, c1992), 403.[/fn]

So, It seems rather clear that the idea of capital punishment is sufficiently included in the phrase “where the sword.” After all, the sword is most definitely an instrument of discipline and in the Roman culture, it killed. Let’s turn our attention to Acts 25:10-11.

• “The charges were serious enough to demand a death penalty. If the accusations were true, Paul said, he was willing to die.”[fn] John F. Walvoord et al., The Bible Knowledge Commentary: An Exposition of the Scriptures (Wheaton, IL: Victor Books, 1983-c1985), 2:423.[/fn]
• “The right of appeal to the supreme power, in case of life and death, was secured by an ancient law to every Roman citizen, and continued under the empire.”[fn] Robert Jamieson et al., A Commentary, Critical and Explanatory, on the Old and New Testaments (On spine: Critical and explanatory commentary; Oak Harbor, WA: Logos Research Systems, Inc., 1997), Ac 25:11.[/fn]
• “Done something for which I deserve the death penalty may be rendered as “done something which should cause me to be killed” or “…for which I should be punished by being killed.” The following clause, do not ask to escape it, may accordingly be rendered as “do not ask not to be killed” or “do not ask to escape death.”[fn] Barclay Moon Newman and Eugene Albert Nida, A Handbook on the Acts of the Apostles (Originally published: A translator’s handbook on the Acts of the Apostles, 1972; UBS handbook series; Helps for translators New York: United Bible Societies, 993], c1972), 462.[/fn]

Paul does not deny the right of the state to execute people. Instead of denouncing capital punishment, Paul assumes its validity and appeals to Caesar as was the right of Roman citizens when a  crime worthy of death and then levied.

Conclusion: The New Testament affirms capital punishment

It seemed clear that the New Testament does not denounce the idea of capital punishment but instead assumes the right of the state to use it.