"Shouldst not thou then have had compassion also on thy fellow servant, even as I had compassion on thee? [34] And his lord being angry, delivered him to the torturers until he paid all the debt. [35] So also shall my heavenly Father do to you, if you forgive not every one his brother from your hearts" (Matthew 18:33-35).
"To thee only have I sinned, and have done evil before thee: that thou mayst be justified in thy words and mayst overcome when thou art judged" (Psalm 51:6).
"And when they were come to the place which is called Calvary, they crucified him there; and the robbers, one on the right hand, and the other on the left. [34] And Jesus said: Father, forgive them, for they know not what they do. But they, dividing his garments, cast lots" (Luke 23:33-34).
"Assuming that the guilty party's identity and responsibility have been fully determined, the traditional teaching of the Church does not exclude recourse to the death penalty, if this is the only possible way of effectively defending human lives against the unjust aggressor.
If, however, non-lethal means are sufficient to defend and protect people's safety from the aggressor, authority will limit itself to such means, as these are more in keeping with the concrete conditions of the common good and are more in conformity to the dignity of the human person.
Today, in fact, as a consequence of the possibilities which the state has for effectively preventing crime, by rendering one who has committed an offense incapable of doing harm - without definitely taking away from him the possibility of redeeming himself - the cases in which the execution of the offender is an absolute necessity 'are very rare, if not practically non-existent'" (Catechism of the Catholic Church 2267).