5:20. And we know that the Son of God is come. And he hath given us understanding that we may know the true God and may be in his true Son. This is the true God and life eternal.
And may be in his true Son. He is, or this is the true God, and life eternal. . .Which words are a clear proof of Christ's divinity, and as such made use of by the ancient fathers.
5:21. Little children, keep yourselves from idols. Amen.
Keep yourselves from idols. . .An admonition to the newly converted Christians, lest conversing with heathens and idolaters, they might fall back into the sin of idolatry, which may be the sin unto death here mentioned by St. John.
THE SECOND EPISTLE OF ST. JOHN THE APOSTLE
The Apostle commends Electa and her family for their steadfastness in the true faith and exhorts them to persevere, lest they lose the reward of their labours. He exhorts them to love one another. But with heretics to have no society, even not to salute them. Although this Epistle is written to a particular person, yet its instructions may serve as a lesson to others, especially to those who, from their connections, situation, or condition in life, are in danger of perversion.
2 John Chapter 1
He recommends walking in truth, loving one another and to beware of false teachers.
1:1. The Ancient to the lady Elect and her children, whom I love in the truth: and not I only, but also all they that have known the truth,
The ancient. . .That is, the ancient bishop St. John, being the only one of the twelve apostles then living. To the lady Elect. . .Some conjecture that Electa might be the name of a family, or of a particular church; but the general opinion is, that it is the proper name of a lady, so eminent for her piety and great charity, as to merit this Epistle from St. John.