1 Jo 3:6 Whoever abides in Him does not sin. Whoever sins has neither seen Him nor known Him.
The apostle John here was not teaching sinless perfection. James himself said: " For we all stumble in many things." (Jas 3:2) Notice, the pronoun used. He included himself as one who stumbles in many things. James did not claim sinless perfection for himself.
Even the apostle John, the very one who wrote 1st John himself said, again notice the pronoun used: "If we say that we have no sin, we deceive ourselves, and the truth is not in us." (1 Jo 1:8)
If John meant sinless perfection here in 1 John 3:6, then he, including James, would be disqualified and would be dismissed as someone who has neither seen the Lord nor known Him. Actually, the emphasis is on the tense of the verbs "sin" and "sins." Consulting other reliable translations, we read:
1Jn 3:6 No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him. NIV
1Jo 3:6 No one who continues in union with Him lives in sin: no one who lives in sin has seen Him or knows Him. WNT
The verse is actually talking about sinning as a lifestyle. It refers to an unchanged life. It's not talking about sinning as an exception in one's life but as something that characterizes it. There's a difference between stumbling into sin as opposed to swimming in it. A mountain of difference between being comfortable about sinning from grieving over it because of occasional slips here and there.
There is another way of looking at this verse. And it is this---it talks about sinning here as being lawless. Stick with me for a moment as I explain it further. Follow me closely. Think with me.
In John 3:4 we read this: "Whoever commits sin also commits lawlessness, and sin is lawlessness."
From this verse down to verse 9, John talks about being lawless. Now, failing to obey God and being lawless are two different things.
A lawless man is someone who does not recognize any moral standard above him. He is a law unto himself. He makes his own rules and recognizes no authority above him. The man in Romans 7 is different. He is not lawless. In fact, he delights in the law. But because of his weakness, he fails to carry out the will of God for his life.
Observe and notice him:
Ro 7:15 For what I am doing, I do not understand. For what I will to do, that I do not practice; but what I hate, that I do.
You see, he wills to obey the law. He hates failing to carry it out.
16 If, then, I do what I will not to do, I agree with the law that it is good.
17 But now, it is no longer I who do it, but sin that dwells in me.
You see, he agrees that the law is good. He is not against it.
18 For I know that in me (that is, in my flesh) nothing good dwells; for to will is present with me, but how to perform what is good I do not find.
See, he wants to perform the law. But has no strength to execute it.
19 For the good that I will to do, I do not do; but the evil I will not to do, that I practice.
20 Now if I do what I will not to do, it is no longer I who do it, but sin that dwells in me.
21 I find then a law, that evil is present with me, the one who wills to do good.
22 For I delight in the law of God according to the inward man.
You see, he delights in the law!
23 But I see another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members.
The man in this section is not lawless, although he is a failure in carrying out the will of God.
Back to 1st John 3:4-9. John is saying that a Christian will never fall into this condition. His heart will always be desiring to obey God's will. But to fall into a condition of lawlessness, that, he won't do.
Whoever sins, in the sense of being lawless, has never seen God nor known Him.
