Whoever remains in him doesn't sin. Whoever sins hasn't seen him, neither knows him.
"In modern times a popular expedient for dealing with the difficulties perceived in 1 John 3:6; 1 John 3:9 is to appeal to the use of the Greek present tense. It is then asserted that this tense necessitates a translation like, ’Whoever has been born of God does not go on sinning,’ or, ’does not continually sin.’ The inference to be drawn from such renderings is that, though the Christian may sin somewhat (how much is never specified!), he may not sin regularly or persistently. But on all grounds, whether linguistic or exegetical, the approach is indefensible.