2:12-14 As Christians have their peculiar states, so they have peculiar duties; but there are precepts and obedience common to all, particularly mutual love, and contempt of the world. The youngest sincere disciple is pardoned: the communion of saints is attended with the forgiveness of sins. Those of the longest standing in Christ's school need further advice and instruction. Even fathers must be written unto, and preached unto; none are too old to learn. But especially young men in Christ Jesus, though they are arrived at strength of spirit and sound sense, and have successfully resisted first trials and temptations, breaking off bad habits and connexions, and entered in at the strait gate of true conversion. The different descriptions of Christians are again addressed. Children in Christ know that God is their Father; it is wisdom. Those advanced believers, who know Him that was from the beginning, before this world was made, may well be led thereby to give up this world. It will be the glory of young persons to be strong in Christ, and his grace. By the word of God they overcome the wicked one.
14. young men … strong—made so out of natural weakness, hence enabled to overcome "the strong man armed" through Him that is "stronger." Faith is the victory that overcomes the world. This term "overcome" is peculiarly John's, adopted from his loved Lord. It occurs sixteen times in the Apocalypse, six times in the First Epistle, only thrice in the rest of the New Testament. In order to overcome the world on the ground, and in the strength, of the blood of the Saviour, we must be willing, like Christ, to part with whatever of the world belongs to us: whence immediately after "ye have overcome the wicked one (the prince of the world)," it is added, "Love not the world, neither the things … in the world."
and, &c.—the secret of the young men's strength: the Gospel word, clothed with living power by the Spirit who abideth permanently in them; this is "the sword of the Spirit" wielded in prayerful waiting on God. Contrast the mere physical strength of young men, Isa 40:30, 31. Oral teaching prepared these youths for the profitable use of the word when written. "Antichrist cannot endanger you (1Jo 2:18), nor Satan tear from you the word of God."
the wicked one—who, as "prince of this world," enthrals "the world" (1Jo 2:15-17; 5:19, Greek, "the wicked one"), especially the young. Christ came to destroy this "prince of the world." Believers achieve the first grand conquest over him when they pass from darkness to light, but afterwards they need to maintain a continual keeping of themselves from his assaults, looking to God by whom alone they are kept safe. Bengel thinks John refers specially to the remarkable constancy exhibited by youths in Domitian's persecution. Also to the young man whom John, after his return from Patmos, led with gentle, loving persuasion to repentance. This youth had been commended to the overseers of the Church by John, in one of his tours of superintendency, as a promising disciple; he had been, therefore, carefully watched up to baptism. But afterwards relying too much on baptismal grace, he joined evil associates, and fell from step to step down, till he became a captain of robbers. When John, some years after, revisited that Church and heard of the youth's sad fall, he hastened to the retreat of the robbers, suffered himself to be seized and taken into the captain's presence. The youth, stung by conscience and the remembrance of former years, fled away from the venerable apostle. Full of love the aged father ran after him, called on him to take courage, and announced to him forgiveness of his sins in the name of Christ. The youth was recovered to the paths of Christianity, and was the means of inducing many of his bad associates to repent and believe [Clement of Alexandria, Who Is the Rich Man Who Shall Be Saved? 4.2; Eusebius, Ecclesiastical History, 3.20; Chrysostom, First Exhortation to Theodore, 11].