John Wesley loved 1 John. He wrote that it contained the essence of biblical faith, and many of his particular doctrinal emphases can be found in that book.
It is one of those books where translation versions make important differences in what you read. For instance, here is 1 John 3:6 in the NIV:
No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him.
And here it is in the NRSV:
No one who abides in him sins; no one who sins has either seen him or known him.
I’ve heard a preacher using the NIV text to argue that the point being made by the apostle is that if we persist in sinning we do not live in Christ. Of course, the preacher said, we all sin. The important issue is whether we make a habit of it or whether we keep on sinning.
This is not John Wesley’s take on this text, which reads in the King James much more like the NRSV than the NIV. For Wesley, here and elsewhere the point of the apostle is that being in Christ is incompatible with any sin. As it says in 1 John 1:5, God is light and in him there is no darkness at all.
For Wesley, abiding in Christ is a moment by moment thing sustained by the active co-operation of the Spirit entering the believer and believer breathing out love and prayer in the Spirit. While we abide in Christ we cannot sin.
I don’t know whether the grammar of the Greek supports the Wesleyan reading or the NIV translation. The verb tense here, though, carries a lot of meaning. Or it seems to.