1 John 4:20

If a man say, I love God, and hateth his brother - This, as well as many other parts of this epistle, seems levelled against the Jews, who pretended much love to God while they hated the Gentiles; and even some of them who were brought into the Christian Church brought this leaven with them. It required a miracle to redeem St. Peter's mind from the influence of this principle. See Acts 10.

Whom he hath seen - We may have our love excited towards our brother,

1. By a consideration of his excellences or amiable qualities.

By a view of his miseries and distresses.

The first will excite a love of complacency and delight; the second, a love of compassion and pity.

Whom he hath not seen? - If he love not his brother, it is a proof that the love of God is not in him; and if he have not the love of God, he cannot love God, for God can be loved only through the influence of his own love. See on 1 John 4:19 ; (note). The man who hates his fellow does not love God. He who does not love God has not the love of God in him, and he who has not the love of God in him can neither love God nor man.