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.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Tract. lxxxiii. 3