Teachings of Jesus:
Do not kill. Do not even be angry!

At this, one of Jesus’ companions drew his sword and struck the servant of the high priest, cutting off his ear. “Put your sword back in its place,” Jesus said to him. “For all who draw the sword will die by the sword. Matthew 26:51-52

Those around Jesus saw what was about to happen and said, “Lord, should we strike with our swords?” And one of them struck the servant of the high priest, cutting off his right ear. But Jesus answered, “No more of this!” And He touched the man’s ear and healed him. Luke 22:49-51

You have heard that it was said to the ancients, ‘Do not murder’ and ‘Anyone who murders will be subject to judgment.’ But I tell you that anyone who is angry with his brother will be subject to judgment. Again, anyone who says to his brother, ‘worthless, good-for-nothing,’ will be subject to the Sanhedrin. But anyone who says, ‘You fool!’ will be subject to the fire of hell. Matthew 5:21-22