Gregory the Great, on 1John 4:20

“If any man say, I love God, and hateth his brother; he is a liar. For he that loveth not his brother, whom he seeth, how can he love God, whom he seeth not?”

“Hence it is that, as we have already said in another sermon, the same Spirit is read to have been given to the disciples twice: first by the Lord while dwelling on earth, afterward by the Lord presiding from heaven. On earth, indeed, he is given that neighbor may be loved; from heaven, truly, that God may be loved. But why first on earth, afterward from heaven, unless it is plainly given to understand that, according to John's voice, "He who does not love his brother whom he sees, how can he love God whom he does not see?" Therefore let us love our neighbor, brothers; let us love him who is near us, that we may be able to arrive at the love of him who is above us.”

Imported from an open dataset — not yet checked against the printed edition.