If you sincerely believe that a person is going to be in Hell when they die wouldn’t the proper thing to do be extending their life as long as possible and making the effort to give them as many chances as to accept salvation? Is there some sort of theological reasoning to explain this beyond the death penalty being used at times in the Bible?
I’m not necessarily a fundamentalist Protestant, nor was the man who addresses the issue here. (CS Lewis).
angelfire.com/pro/lewiscs/humanitarian.html
If I may cherry-pick a few sentences that pertain most directly to the OP:
“I do not know whether a murderer is more likely to repent and make good on the gallows a few weeks after his trial or in the prison infirmary thirty years later.”
I agree with this; I don’t know if you can demonstrate that immanent death is more or less of a deterrent to justification than life in a cell and death of old age. With that in mind, there are other factors that explain why a Protestant might be supportive of capital punishment. In summary of the reasoning put forward by Lewis, the claims of the Humanitarian approach to justice are flawed in several ways, and while no system can ever be carried out infallibly at all times, a return to the more traditional philosophy of retribution would be more right and more just for all parties concerned.
Central to this argument is the concept of Desert. “The Humanitarian theory removes from Punishment the concept of Desert. But the concept of Desert is the only connecting link between punishment and justice. It is only as deserved or undeserved that a sentence can be just or unjust. I do not here contend that the question ‘Is it deserved?’ is the only one we can reasonably ask about a punishment. We may very properly ask whether it is likely to deter others and to reform the criminal. But neither of these two last questions is a question about justice.”
I suppose the thesis statement would be this: Protestants who support capital punishment do so because they believe it is more just than other alternatives, in the sense that some criminals deserve to die- and when this is true, the “concept of Desert” is the only connecting link between punishment and justice.
God Bless!