Matthew Henry's Concise Commentary on the Bible - 1 John 5:1-5
1-5 True love for the people of God, may be distinguished from natural kindness or party attachments, by its being united with the love of God, and obedience to his commands. The same Holy Spirit that taught the love, will have taught obedience also; and that man cannot truly love the children of God, who, by habit, commits sin or neglects known duty. As God's commands are holy, just, and good rules of liberty and happiness, so those who are born of God and love him, do not count them grievous,... read more
George Haydock's Catholic Bible Commentary - 1 John 5:21
Keep yourselves from idols. An admonition to the new 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. (Witham) read more