William Barclay's Daily Study Bible - 1 John 5:21
5:21 My dear children, guard yourselves from idols. With this sudden, sharp injunction John brings his letter to an end. Short as it is, there is a world of meaning in this phrase. (i) In Greek the word idol has in it the sense of unreality. Plato used it for the illusions of this world as opposed to the unchangeable realities of eternity. When the prophets spoke of the idols of the heathen, they meant that they were counterfeit gods, as opposed to the one true God. This may well mean,... read more
Matthew Henry's Complete Commentary - 1 John 5:18-21
Here we have, I. A recapitulation of the privileges and advantages of sound Christian believers. 1. They are secured against sin, against the fulness of its dominion or the fulness of its guilt: We know that whosoever is born of God (and the believer in Christ is born of God, 1 John 5:1) sinneth not (1 John 5:18), sinneth not with that fulness of heart and spirit that the unregenerate do (as was said 1 John 3:6, 9), and consequently not with that fulness of guilt that attends the sins of... read more