Church Fathers on Luke 6:35

The Lord had said that we must love our enemies, but that you might not think this an exaggerated expression, regarding it solely as spoken to alarm them, he adds the reason, saying, For if you love them which love you, what thank have you? There are indeed several causes which produce love; but spiritual love exceeds them all. For nothing earthly engenders it, neither gain, nor kindness, nor nature, nor time, but it descends from heaven. But why wonder that it needs not…

But he not only condemns as unprofitable the love and kindness of sinners, but also the lending. As it follows, And if you lend to those from whom you hope to receive, what thank have you? for sinners also lend to sinners, to receive as much again.

Now philosophy seems to divide justice into three parts; one towards God, which is called piety; another towards our parents, or the rest of mankind; a third to the dead, that the proper rites may be performed. But the Lord Jesus passing beyond the oracle of the law, and the heights of prophecy, extended the duties of piety to those also who have injured us, adding, But love your enemies.