1 John 5:3

And by what do we know that we love the sons of God? By this, "that we love God, and do His commandments." We sigh here, by reason of the hardness of doing the commandments of God. Hear what follows. O man, at what toilest thou in loving? In loving avarice. With toil is that loved which thou lovest: there is no toil in loving God. Avarice will enjoin thee labors, perils, sore hardships and tribulations; and thou wilt do its bidding. To what end? That thou mayest have that with which thou shalt fill thy chest, and lose thy peace of mind. Thou didst feel thyself haply more secure before thou hadst it, than since thou didst begin to have. See what avarice has enjoined thee. Thou hast filled thine house, and art in dread of robbers; hast gotten gold, lost thy sleep. See what avarice has enjoined thee. Do, and thou didst. What does God enjoin thee? Love me. Thou lovest gold, thou wilt seek gold, and perchance not find it: whoso seeks me, I am with him. Thou wilt love honor, and perchance not attain unto it: who ever loved me, and did not attain?

God saith to thee, thou wouldest make thee a patron, or a powerful friend: thou seekest a way to his favor by means of another inferior. Love me, saith God to thee: favor with me is not had by making interest with some other: thy love itself makes me present to thee. What sweeter than this love, brethren? It is not without reason that ye heard just now in the Psalm, "The unrighteous told me of delights, but not as is Thy law, O Lord." What is the Law of God? The commandment of God. What is the commandment of God? That "new commandment," which is called new because it maketh new: "A new commandment give I unto you, that ye love one another." Hear because this is the law of God. The apostle saith, "Bear ye one another's burdens, and so shall ye fulfill the law of Christ." This, even this, is the consummation of all our works; Love. In it is the end: for this we run: to it we run; when we are come to it, we shall rest.

"For this is the love of God, that we keep His commandments." Already ye have heard, "On these two commandments hang all the law and the prophets." See how He would not have thee divide thyself over a multitude of pages: "On these two commandments hang all the law and the prophets." On what two commandments? "Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. And, thou shalt love thy neighbor as thyself. On these two commandments hang all the law and the prophets."

See here of what commandments this whole epistle talks. Therefore hold fast love, and set your minds at rest. Why fearest thou lest thou do evil to some man? Who does evil to the man he loves? Love thou: it is impossible to do this without doing good. But it may be, thou rebukest? Kindness does it, not fierceness. But it may be thou beatest? For discipline thou dost this; because thy kindness of love will not let thee leave him undisciplined. And indeed there come somehow these different and contrary results, that sometimes hatred uses winning ways, and charity shows itself fierce. A person hates his enemy, and feigns friendship for him: he sees him doing some evil, he praises him: he wishes him to go headlong, wishes him to go blind over the precipice of his lusts, haply never to return; he praises him, "For the sinner is praised in the desires of his soul;" he applies to him the unction of adulation; behold, he hates, and praises.

Another sees his friend doing something of the same sort; he calls him back; if he will not hear, he uses words even of castigation, he scolds, he quarrels: there are times when it comes to this, that one must even quarrel! Behold, hatred shows itself winningly gentle, and charity quarrels! Stay not thy regard upon the words of seeming kindness, or the seeming cruelty of the rebuke; look into the vein they come from; seek the root whence they proceed. The one is gentle and bland that he may deceive, the other quarrels that he may correct.