3:11-15 We should love the Lord Jesus, value his love, and therefore love all our brethren in Christ. This love is the special fruit of our faith, and a certain sign of our being born again. But none who rightly know the heart of man, can wonder at the contempt and enmity of ungodly people against the children of God. We know that we are passed from death to life: we may know it by the evidences of our faith in Christ, of which love to our brethren is one. It is not zeal for a party in the common religion, or affection for those who are of the same name and sentiments with ourselves. The life of grace in the heart of a regenerate person, is the beginning and first principle of a life of glory, whereof they must be destitute who hate their brother in their hearts.

14. We—emphatical; hated though we be by the world, we know what the world knows not.

know—as an assured fact.

passed—changed our state. Col 1:13, "from the power of darkness … translated into the kingdom of His dear Son."

from death unto life—literally, "out of the death (which enthrals the unregenerate) into the life (of the regenerate)." A palpable coincidence of language and thought, the beloved disciple adopting his Lord's words.

because we love the brethren—the ground, not of our passing over out of death into life, but of our knowing that we have so. Love, on our part, is the evidence of our justification and regeneration, not the cause of them. "Let each go to his own heart; if he find there love to the brethren, let him feel assured that he has passed from death unto life. Let him not mind that his glory is only hidden; when the Lord shall come, then shall he appear in glory. For he has vital energy, but it is still wintertime; the root has vigor, but the branches are as it were dry; within there is marrow which is vigorous, within are leaves, within fruits, but they must wait for summer" [Augustine].

He that loveth not—Most of the oldest manuscripts omit "his brother," which makes the statement more general.

abideth—still.

in death—"in the (spiritual) death" (ending in eternal death) which is the state of all by nature. His want of love evidences that no saving change has passed over him.