1 John 5:21

“Little children, keep yourselves from idols, Amen.] From Heathen idols and idolatry, into which the saints in those times might be liable to be drawn, by reason of their dwelling among Heathen idolaters, and being related to them, and by the too great freedom used in eating things sacrificed to idols in their temples; and from all other idols that might be introduced by some who went by the name of Christians, as the Gnostics, who worshipped the images of Simon and Helena; and the passage may be an antidote against the worshipping of images, afterwards introduced by the Papists. Moreover, errors and false doctrines, which are the figments of men's minds, and what they are fond of, may be…”

“Affectionate parting caution. from idols--Christians were then everywhere surrounded by idolaters, with whom it was impossible to avoid intercourse. Hence the need of being on their guard against any even indirect compromise or act of communion with idolatry. Some at Pergamos, in the region whence John wrote, fell into the snare of eating things sacrificed to idols. The moment we cease to abide "in Him that is true (by abiding) in Jesus Christ," we become part of "the world that lieth in the wicked one," given up to spiritual, if not in all places literal, idolatry (Eph 5:5; Col 3:5). Next: 2 John Introduction”

“Little children - This is a favorite mode of address with John, (see the notes at 1 John 2:1), and it was proper to use it in giving his parting counsel; embracing, in fact, all that he had to say - that they should keep themselves from idols, and suffer nothing to alienate their affections from the true God. His great object had been to lead them to the knowledge and love of God, and all his counsels would be practically followed, if, amidst the temptations of idolatry, and the allurements of sin, nothing were allowed to estrange their hearts from him. Keep yourselves from idols - From worshipping them; from all that would imply communion with them or their devotees. Compare the notes at 1…”

“Keep yourselves from idols - From all worship of false gods, from all worship of images or of any creature, and from every inward idol; from loving, desiring, fearing anything more than God. Seek all help and defence from evil, all happiness in the true God alone. Next: 2 John Chapter 1”

“5:21 In closing, John exhorts his flock to keep away from anything that might take God’s place in your hearts (literally keep yourselves from idols). In the context of 1 John, the primary idol would be any false teaching that takes people away from Jesus Christ, who is at once fully man and fully God.”

“Little: Jo1 2:1 keep: Exo 20:3, Exo 20:4; Co1 10:7, Co1 10:14; Co2 6:16, Co2 6:17; Rev 9:20, Rev 13:14, Rev 13:15, Rev 14:11 Amen: Mat 6:13 Next: 2 John Chapter 1”