***(DISCLAIMER: This article is by no means comprehensive on this question, nor am I a theologian or a credited specialist on this topic. It is meant merely as a general, basic springboard for discussion)***
Can a Christian support the death penalty? The case for the death penalty is a very nuanced and complex subject to explain in a short article, but a Christian could make the beginning of a case in support of capital punishment by focusing on two basic principles: (1) natural law, or in other words, “the universal, practical obligatory judgements of reason, knowable by all men as binding them to do good and avoid evil, and discovered by right reason from the nature of man adequately considered” , and (2) Holy Scripture.
What does natural law mean? Well, even the words “natural” and “law” provide a basic understanding of the term: “natural”, as in not man-made nor supernatural, but coming from the very nature of things that we can know prior to any instruction; and “law”, as in a set of precepts that dictate how something works. Natural law is the set of precepts that follows from the principle that as human beings, we have an inherent rationality that points us toward good and away from evil.
What are the goods that natural law directs us towards? Well, Thomas Aquinas, an immensely influential philosopher and theologian, tells us that the three general categories of goods inherent in human nature are: (a) self-preservation, (b) continued existence of the species by child-bearing, and (c) the desire to know about first things and to live in a society without “offending those among whom one has to live”. Taking these goods in mind, we can take the logical step that it is our obligation, and even our moral obligation, simply because it is good to do so.
One ought to do good, which is to say, do what is necessary to satisfy the ends that nature dictates. Everyone acts in a way to achieve some good and avoid some evil. Even the one who is doing some “bad” is meaning to do something they perceive to be good and avoid what they perceive to be evil. For example, a drug dealer, while dealing drugs, is making money which he sees as achieving some good (i.e. gaining money) to avoid some evil (i.e. destitution). However, the distinction between the actual good and the actual evil is inherent in human nature. Though the drug dealer may be directed toward some good, he is very aware he is engaging in evil, because it is an act that deprives another person of a good. This is, of course, considered a violation of natural law, because we see that we are all equally directed by nature toward these ends.
As societal beings, and all ordered by natural law toward good, we direct ourselves in a way that is necessary in order to preserve our right and the rest of mankind’s to pursue what nature dictates us all to do. As to these inherent rights of nature, one would say they are, among others, the right to life, property, and freedom, for these provide us with the tools to pursue our natural ends.
The next step in looking at the legitimacy of capital punishment is to see why punishment itself is necessary. When an individual acts contrary to natural law, he fails to recognize the necessary connection between realizing his natural ends and achieving happiness, as well as the connection between not realizing those ends and receiving pain. These are the necessary feelings nature uses to direct us to our ends. Punishment is necessary to restore these connections to recognition. A natural law philosopher puts it better:
That is what crime and sin are – the inordinate indulging of our own will or the inordinate securing of pleasure at the expense of the law or of the order required by reason. The restoration of the right order of pleasures by the infliction of a proportionate pain is what we mean by retributive punishment. 
Considering the different proportions of good acts and bad acts, it should be understood that the reward should be proportional to the good act and the punishment proportional to the bad act. It is through the concept of retribution, or “inflicting on the offender a harm proportionate to his offense”,  that we can naturally assume that some wrongdoings are so grave they deserve punishments that are proportionate in severity.
Finally, the next logical step would be to decide who has the right to inflict this punishment. When the offender offends, he offends the order of things, and it becomes the responsibility of the head of that order to inflict that punishment as a means to correct the disorder.
By using what we know about natural law and all that that implies, we can reasonably deduce the following chain of logic:
- Wrongdoers deserve punishment.
- The graver the wrongdoing, the more severe the punishment deserved.
- Some wrongdoings are so grave that no punishment less than death would be proportionate in its severity.
- Therefore, wrongdoers of such a crime should be put to death.
- Public authorities have the right, in principle, to inflict on the wrongdoers punishments they deserve.
- Therefore, public authorities have the right, in principle, to inflict the death penalty on those guilty of the gravest offences.
By these logical steps, we see that the case for capital punishment can be made by the principle of natural law.
Now, as Christians, we believe that God is the Logos, or the ground of logic and reason, which dictates us to follow natural law. However, as stated before, natural law is neither man-made nor supernatural, so we should look to Scripture to further strengthen our case that God intended capital punishment to be divine law as well. The Old Testament provides many citations that back the exercise of capital punishment, but we will focus on the three that makes the greatest case.
First, God provides the proper reason why capital punishment should be executed on man by man in Genesis when He tells Noah and his sons that “‘whoever sheds the blood of man, shall his blood be shed; for God made man in his own image'” (9:1, 5-6).
Second, God provides the principle of proportionate justice when He orders: “He who kills a man shall be put to death…as he has done it shall be done to him” (Lev. 24:17, 19-20).
And third, God provides the principle of the authority’s right to execute capital punishment: “But if any man hates his neighbor…wounds his mortally so he dies…hand him over to the avenger of blood, so that he may die” (Deut. 19:11-13).
To fully defend a Christian’s support of capital punishment, one would also have to show scriptural proof from the New Testament as well. These five points include both scriptural evidence but also responses to certain passages used by some to attempt to prove that Jesus was against capital punishment.
First, many use this passage from the Sermon on the Mount to say that Jesus was arguing against capital punishment: “Anyone strikes you on the right cheek, turn to him the other also” (Matt. 5:38-41). The issues with using this as an argument against capital punishment are that this passage only seems to address individual revenge and not societal retribution, and that in the same sermon, Jesus tells His followers that He had come to reaffirm the law of the Old Testament and not change it.
Second, many use this passage from the story about the woman doomed to be stoned for adultery, and how Jesus told the crowd of people about to stone this woman: “He that is without sin, cast the first stone” (John 8:1-11). The issue with using this passage is that Jesus never denies that the punishment is unjust at all but only that the crowd was guilty of hypocrisy.
Third, at Jesus’s crucifixion, the good thief who was being crucified next to Jesus, tells Jesus that his and his counterpart’s punishment was “justly” and their “due reward” and that he accepts it for his crime (Luke 23:41). Jesus never criticizes this outlook nor suggests that the statement is contrary to his human dignity, nor would Luke have provided the thief’s words if he believed it was contrary to the teachings of Christ.
Fourth, St. Paul says this when defending his life before Festus: “If then I am a wrongdoer, and have committed anything for which I deserve to die, I do not seek to escape death” (Acts 25:11). Saint Paul is implying that there are crimes grave enough to be worthy of the severity of capital punishment, but that he is innocent of such a crime.
Fifth, this New Testament verse affirms the state’s right to execute offenders: “…But if you do wrong, be afraid, for [the governing authority] does not bear the sword in vain; he is the servant of God to execute his wrath on the wrongdoer” (Rom. 13:1-4).
The comprehensive Christian argument in support of the death penalty is much more complicated and nuanced than this article could possibly cover, and in fact, what may be considered the full argument may not be completely done yet. However, the beginnings of the case are there, and it is with these starting principles that we can further flesh out and address this very relevant question of today.
 Bernard Wuellner, Dictionary of Scholastic Philosophy (Milwaukee: Bruce, 1956), pp. 68-69.
 Thomas Aquinas, Summa Theologica I-II, 94, 2.
 Cronin, Science of Ethics, 1:588.
 Edward Feser, Joseph M. Bessette, By Man Shall His Blood Be Shed (San Francisco: Ignatius Press, 2006), pp. 46.
Edward Feser, Joseph M. Bessette, By Man Shall His Blood Be Shed (San Francisco: Ignatius Press, 2006).