1 John 3:6

Whosoever abideth in him sinneth not: whosoever sinneth hath not seen him, neither known him.

Christ's entire separation from sin implies that those in Him must also be separate from it.

Abideth in him - as the branch in the vine, by vital union, living by His life.

Sinneth not. So far as he abides in Christ, he is free from all sin. The ideal of the Christian. The life of sin and the life of God exclude one another, as darkness and light. In matter of fact, believers do fall into sins (1 John 1:8; 1 John 1:10; 1 John 2:1); but all sins are alien from the life of God, and need Christ's cleansing blood, without application to which the life of God could not be maintained. He sinneth not so long as he abideth in Christ. He that falls into sin is a man: he that boasts of sin is a devil: he that grieves at sin is a saint (Fuller).

Whosoever sinneth hath not seen him, [ heooraken (G3708)] - 'has not seen, and does not see Him.' The ideal of Christian intuitive knowledge is presented, John 10:4. All sin is at variance with the notion of one regenerated. Not 'whosoever is betrayed into sins has never seen, nor known' God; but in so far as sin exists, in that degree spiritual intuition of God doth not exist in him.

Neither - `not even.' To see spiritually is a further step than to know; for by knowing we come to seeing by vivid, experimental realization.