Discovery Box1 John 4:20-21 
Context4:20 If anyone says 1 “I love God” and yet 2 hates his fellow Christian, 3 he is a liar, because the one who does not love his fellow Christian 4 whom he has seen cannot love God whom he has not seen. 5 4:21 And the commandment we have from him is this: that 6 the one who loves God should love his fellow Christian 7 too.
1 tn Grk “if anyone should say…”
2 tn “Yet” is supplied to bring out the contrast.
3 tn See note on the phrase “fellow Christian” in 2:9.
4 tn See note on the phrase “fellow Christian” in 2:9.
5 sn In 4:20 the author again describes the opponents, who claim to love God. Their failure to show love for their fellow Christians proves their claim to know God to be false: The one who does not love his fellow Christian whom he has seen cannot love God whom he has not seen.
6 tn The ἵνα (Jina) clause in 4:21 could be giving (1) the purpose or (2) the result of the commandment mentioned in the first half of the verse, but if it does, the author nowhere specifies what the commandment consists of. It makes better sense to understand this ἵνα clause as (3) epexegetical to the pronoun ταύτην (tauthn) at the beginning of 4:21 and thus explaining what the commandment consists of: “that the one who loves God should love his brother also.”
