1 John 5:3 New English Translation

³For^[a] this is the love of God:^[b] that we keep his commandments.^[c] And his commandments do not weigh us down,

1 John 5:3 tn The force of the γάρ (gar) at the beginning of 5:3 is similar to another introductory formula used by the author of 1 John, καὶ αὕτη ἐστίν (kai hautē estin; used in 1:5; 5:4, 11, and 14). The γάρ draws an inference based on the preceding statements, particularly the one in 5:2b, regarding the love of God. If in 5:2 loving God and keeping his commandments is the key to knowing that we love God’s children, it is important to define what the love of God involves, and this is what the author is doing in 5:3. In fact, as the following ἵνα (hina) clause makes clear, loving God consists in keeping his commandments.
1 John 5:3 tn Once again the genitive could be understood as (1) objective, (2) subjective, or (3) both. Here an objective sense is more likely (believers’ love for God) because in the previous verse it is clear that God is the object of believers’ love.
1 John 5:3 tn Contrary to the punctuation of NA²⁸ and UBS⁵, it is best to place a full stop (period) following τηρῶμεν (tērōmen) in 5:3. The subordinate clause introduced by ὅτι (hoti) at the beginning of 5:4 is related to the second half of 5:3 which begins with καί (kai). Καί is commonly used by the author to begin a new sentence, probably by analogy with the Hebrew vav consecutive.

New English Translation (NET)