No, if done properly I would consider it merciful. Here are just four ways:
- It gives them a certainty of their very impending death, prompting repentance.
- If not repentant, it gives them less chance to add further sins to their soul
- It is merciful for others, as it protects others (including criminals in prison) from the one who committed the capital offense.
- It is merciful to the victims, who now know there is no way they will escape from prison and come after them
The thing to consider is which is better, it’s not that one way is just always bad, methinks. And the mind of the Church seems to be moving away from capital punishment, so I will opt for their judgment. In my country, which still has capital punishment, we hold them for DECADES before killing them, which is just awful in my opinion, and negates some of the benefits. We also may have a cultural defect in understanding retributive justice. And of course, you never want to punish someone so far for something they didn’t do (getting the wrong guy/gal).
If fear of impending physical death, and/or eternal death of the soul prompts one to repentance, is it sincere or insincere? Can man always know like God? Fear is also known to drive people away from God.
If not sincerely repentant at the time of death, their death has robbed them of any chance to. One must bear in mind, ‘‘not every soul recovers instantaneously from its wounds. Some do so by successive stages, which are often slow, and subject to relapse.’’ It’s essential to have patient mercy, which gives souls the time to recover and fortify themselves.
To take another’s life into their own hands, one risks the possibility of being responsible for that soul dying as an innocent, or guilty in an insincere state of repentance, and/or robbed of the opportunity to reach sincere repentance and holiness.
Additionally, while one’s death may prevent further sins to their soul, it has caused others to add sins to their soul if they called for one’s death out of anger, or vengeance, for Jesus says whosoever is angry with their brother will be in danger of the judgment (Mat. 5:22), and vengeance is God’s (Rom. 12:19).
In conclusion, you have not shown how the death penalty can be merciful to the one sentenced to die, or others at least in the way that matters. Also, Jesus taught: “Be ye therefore merciful, as your Father also is merciful.” (Lk. 6:36). Merciful to whom? He made no distinction between sinners. Therefore, why should one pick and choose who should not receive mercy in the face of death?
"Judge not, and you shall not be judged. Condemn not, and you shall not be condemned. Forgive, and you shall be forgiven.’’ (Lk. 6:37)