Fifth Commandment: Murderous Anger (LC I 179-187)

The cause and need of this commandment is that God well knows that the world is evil, and that this life has much unhappiness. Therefore, He has set up this and the other commandments between the good people and the evil. Now, just as there are many attacks on all commandments, so the same happens also with this commandment. We must live among many people who do us harm, and we have a reason to be hostile to them. (183)