5:13-15 The gospel is a doctrine according to godliness, 1Ti 6:3, and is so far from giving the least countenance to sin, that it lays us under the strongest obligation to avoid and subdue it. The apostle urges that all the law is fulfilled in one word, even in this, Thou shalt love thy neighbour as thyself. If Christians, who should help one another, and rejoice one another, quarrel, what can be expected but that the God of love should deny his grace, that the Spirit of love should depart, and the evil spirit, who seeks their destruction, should prevail? Happy would it be, if Christians, instead of biting and devouring one another on account of different opinions, would set themselves against sin in themselves, and in the places where they live.
14. all the law—Greek, "the whole law," namely, the Mosaic law. Love to God is presupposed as the root from which love to our neighbor springs; and it is in this tense the latter precept (so "word" means here) is said to be the fulfilling of "all the law" (Le 19:18). Love is "the law of Christ" (Ga 6:2; Mt 7:12; 22:39, 40; Ro 13:9, 10).
is fulfilled—Not as received text "is being fulfilled," but as the oldest manuscripts read, "has been fulfilled"; and so "receives its full perfection," as rudimentary teachings are fulfilled by the more perfect doctrine. The law only united Israelites together: the Gospel unites all men, and that in relation to God [Grotius].