A.T. Robertson Commentary 1 John 3:5

"And ye know that he was manifested to take away sins; and in him is no sin." — 1 John 3:5 (ASV)

He (εκεινος). As in verse 3; John 1:18.

Was manifested (εφανερωθη). Same form as in verse 2, but here of the Incarnation as in Joh 21:1, not of the second coming (1 John 2:28).

To take away sins (ινα τας αμαρτιας αρη). Purpose clause with ινα and first aorist active subjunctive of αιρω as in Joh 1:29. In Isa 53:11 we have αναφερω for bearing sins, but αιρω properly means to lift up and carry away (John 2:16). So in Heb 10:4 we find αφαιρεω and Heb 10:11 περιαιρεω, to take away sins completely (the complete expiation wrought by Christ on Calvary). The plural αμαρτιας here, as in Col 1:14, not singular (collective sense) αμαρτιαν as in Joh 1:29.

And in him is no sin (κα αμαρτια εν αυτω ουκ εστιν). "And sin (the sinful principle) in him is not." As Jesus had claimed about himself (John 7:18; John 8:46) and as is repeatedly stated in the N.T. (2 Corinthians 5:21; Hebrews 4:15; Hebrews 7:26; Hebrews 9:13).