Actually, the Bible says a lot about the subject, so much so that I can’t treat it in just a short bit of writing. But I’ll do my best to keep it focused, and then you can leave a comment, or talk to me on the Q&A Forum.
First of all, we know that people are created in the image of God (Gen. 1.26-27). Though there is no shortage of opinions about what this means, it at least gives humans a uniqueness among all other beings created, and it also gives a certain status, dignity, and value that are not given to animal life.
From Gen. 1.29-30, we find that nothing at all of animal life is to be killed. At no point is anything allowed to take the life of another living being.
When we get to Genesis 4, Cain murders his brother Abel. It’s interesting to see in v. 14 that Cain expects to die for what he has done, presumably in a “blood feud” sense. God protects him, though, not wanted the world to turn into gangs of vengeful vigilantes. Unfortunately, though predictably, things quickly get out of control, and by Gn. 4.23 it seems that human life has become cheap, that retaliation knows no bounds, and the world is a quagmire of violence. Without the restraints of “an eye for an eye,” it turns into “your life whenever I feel like killing.” Society is steeped in murder that is not punished.
Things turn so bad so quickly that God curbs their sin with a flood to give humankind a chance at life, and he starts over. In Genesis 9.1-6, he makes some rules:
- I want life to thrive. That is the point (9.1).
- Life’s relationships, therefore, have to change. Mankind cannot be trusted to restrain his thirst to kill indiscriminately, so fear is instilled in the animals for their protection. God wishes to protect the preciousness of life from indiscriminate killing (9.2).
- The terms of survival have changed. Certain killing is allowed in an effort to sustain human life. (9.3)
- The blood of animals, representing their life, still has a sacredness to it, therefore life is to be treated with respect, even when it is killed. Men are not to act like animals. (9.4) in random, bloodthirstiness.
- The same standard applies to other people. The blood of people (their life) is sacred, and we are accountable for the preservation of and respect for life. (9.5).
- Capital punishment is instituted, because people are made in the image of God. There is an aspect of divinity involved, and human life is to be protected by other humans. When someone disrespects human life by killing, civil government is to exercise judicial power to control the rampage of sin. Revenge is not sanctioned, but justice, displaying judgment against the ultimate violation of God’s image (9.6).
- The emphasis is placed on life and production, not death and destruction (9.7).
In an effort to keep this paper brief, through the books of Exodus, Deuteronomy, and Leviticus, many other commands are given to civil government as to what situations call for the death penalty, affirming repeatedly that human life is so sacred that the destruction of it is not to be ignored.
Now, you may be wondering: Did the New Testament change anything? Hmmmm…
In Matthew 5.17-19, we hear Jesus endorsing the Law of Moses. In verses 21-22, there is nothing Jesus says that takes away from the Law, or lessens it. In fact, Jesus seems to make things even more strict, though he is not calling for the death penalty for anger. Where he deals with the “eye for an eye” teaching, he is referring to personal matters, not civil ones. Consistently with what is taught in the Old Testament, there is no desire for human life to be treated so cheaply that retaliation is out of control and life to become a bloodfest. Let the government take care of the issues of assault and murder; you be peace-loving as an individual. The verses don’t negate capital punishment, but instead try to control personal attitudes of revenge and retaliation.
In John 8.1-11, a woman caught in adultery (a capital crime in Leviticus) is brought to Jesus. Notice that Jesus doesn’t make an exception here, but instead calls them to follow the reasonableness of civil law. According to the Law, and to prevent abuse and personal vendettas, there must be two or three accusers to establish the fact of guilt. When there was an insufficient number of accusers, Jesus dealt with her redemptively.
Lastly, in Romans 13.1-7, Paul calls his readers to submit to the authority of civil government, which “bears the sword” (v. 4).
Clearly the Bible teaches the legitimacy of the death penalty. Though you may argue that it is not an effective deterrent, the point is not just to deter but also to recognize the sacredness of human life. A modern society that outlaws the death penalty does not send a message of reverence for life, but a message of moral confusion. When we outlaw the death penalty, we tell the murderer that, no matter what he may do to innocent people in our custody and care, women, children, old people, his most treasured possession—his life—is secure. We guarantee it in advance. Just as a nation that declares that nothing will make it go to war finds itself at the mercy of warlike regimes, so a society that will not put the worst of its criminals to death will find itself at the mercy of criminals who have no qualms about putting innocent people to death.
 Patrick J. Buchanan, Right From the Beginning