You have heard that it has been said, You shall love your neighbor, and hate your enemy.
Read Chapter 5
Augustine of Hippo
AD 430
For without this love, wherewith we are commanded to love even our enemies and persecutors, who can fully carry out those things which are mentioned above? Moreover, the perfection of that mercy, wherewith most of all the soul that is in distress is cared for, cannot be stretched beyond the love of an enemy; and therefore the closing words are: Be therefore perfect, even as your Father who is in heaven is perfect. Yet in such a way that God is understood to be perfect as God, and the soul to be perfect as a soul.
And hate thy enemy. The words of the law (Leviticus xix. 18.) are only these: thou shalt love thy friend as thyself; but by a false gloss and inference, these words, and hate thy enemy, were added by the Jewish doctors. (Witham)
See how He has set the highest pinnacle on our good deeds. For this is why He teaches not only to endure a blow, but to offer the right cheek also; not only to add the cloak to the coat, but to travel also two miles with him who compels you to go one; in order that you might receive with all facility that which is much more than these. But what, one may say, is more than these? Not even to count as an enemy him who is doing these things: or rather even somewhat else more than this. For He said not, do not hate, but love; He said not, do not injure, but do good.
Whether, he says, it be a friend or an enemy, a believer or an unbeliever, do good to the person in need. Do not follow the Jewish law that focuses repayment primarily on friends. For this reason, when they were urging the Lord to heal the son of the royal officer, they said to him, “He is worthy to have you do this for him,” because “he has even built us our synagogue.”