The effect of abiding in Christ is that sin is excluded. In the sense in which John means it, this is true of every Christian and not just of a few.
Anyone not already engaged in purifying himself has not seen the purity of Christ. No one will suddenly develop a love for purity the day he crosses into eternity when he has never had it before. The man who is trying to have the best of both worlds will lose both heaven and earth.
How can John say, ‘Whosoever abideth in him sinneth not’, when he has previously written, ‘If we say we have no sin, we deceive ourselves, and the truth is not in us’? Does he contradict himself so quickly, and on such a key point? Certainly not. That conclusion would have to be rejected even if this was only a human composition; far more so when we are dealing with God’s word. Those who only argue with Scripture forfeit the blessing of its instruction.
Does John here teach sinless perfection? Does he mean that the believer is no longer capable of sin? No, in 1 John 3:6-10 he is not speaking of every detail or of every particular act in a believer’s life, but he is speaking of the tendency of that life, the direction of that life, the powerful influence of Christ on that life. He refuses to characterise the Christian life as anything other than a life that rejects sin. He therefore uses the present tense which in Greek is continuous: ‘Whoever abides in him does not keep on sinning.’ On the other hand 1 John 1:8 does refer to particular acts and shows that no Christian can honestly claim sinless perfection.
Does John here teach that sanctification can be achieved by ‘abiding in Christ’, a technique taught by the Higher Life movement which avoids any effort on the part of the Christian and hands the battle to the Lord who takes over from us? Such a view is not credible for John’s letter contains frequent warnings, commandments and exhortations. To abide is not something passive, but ‘to walk as he walked’ (1 John 2:6), to keep his commandments, positive and negative, and to abide in his doctrine.