Augustine of Hippo
Catena Aurea · Johannesevangelium 15
This is my commandment, That ye love one another, as I have loved you. Greater love hath no man than this, that a man lay down his life for his friends. Ye are my friends, if ye do whatsoever I command you. Henceforth I call you not servants; for the servant knoweth not what his Lord doeth: but I have called you friends; for all things that I have heard of my Father I have made known unto you. Ye have not chosen me, but I have chosen you, and ordained you, that ye should go and bring forth fruit, and that your fruit should remain: that whatsoever ye shall ask of the Father in my name, he may give it you.
(Tract. lxxxiii. 3) Where then love is, what can be wanting? where it is not, what can profit? But this love is distinguished from men’s love to each other as men, by adding, As I have loved you. To what end did Christ love us, but that we should reign with Him? Let us therefore so love one another, as that our love be different from that of other men; who do not love one another, to the end that God may be loved, because they do not really love at all. They who love one another for the sake of having God within them, they truly love one another.