[2:3] 1 tn The translation of καί (kai) at the beginning of 2:3 is important for understanding the argument, because a similar καί occurs at the beginning of 1:5. The use here is not just a simple continuative or connective use, but has more of a resumptive force, pointing back to the previous use in 1:5.
[2:3] 2 tn Grk “know him.” (1) Many take the third person pronoun αὐτον (auton) to refer to Jesus Christ, since he is mentioned in 2:1 and the pronoun αὐτός (autos) at the beginning of 2:2 clearly refers to him. But (2) it is more likely that God is the referent here, since (a) the assurance the author is discussing here is assurance that one has come to know God (all the claims of the opponents in 1:5-2:11 concern knowing and having fellowship with the God who is light); (b) when Jesus Christ is explicitly mentioned as an example to follow in 1 John 2:6, the pronoun ἐκεῖνος (ekeinos) is used to distinguish this from previous references with αὐτός; (c) the καί (kai) which begins 2:3 is parallel to the καί which begins 1:5, suggesting that the author is now returning to the discussion of God who is light, a theme introduced in 1:5. The author will now discuss how a Christian may have assurance that he or she has come to know the God who is light.
[2:4] 3 tn Grk “know him.” See the note on the phrase “know God” in 1 John 2:3 for explanation.