^^^The context there does not negate what is said only 1 chapter later.
Dont leave out the next verses!!
3 We know that we have come to know him if we keep his commands. 4 Whoever says, I know him, but does not do what he commands is a liar, and the truth is not in that person. 5 But if anyone obeys his word, love for God[a] is truly made complete in them. This is how we know we are in him: 6 Whoever claims to live in him must live as Jesus did. <- And Christ lived sinlessly in full devotion to God. This is why there is no contradiction in the coming verses.
What is the difference of sinning everyday and not having a "lifestyle marked by it," as you would put it?
Paul and John both state that someone reborn in Spirit will no longer deliberately sin nor live in sin.
Hebrews 10:26
1 John 3:6
1 John 3:9-10 (he repeats himself here)
1 John 5:18
These statements are very blunt, to the point, and hard to refute. That said, I know I still sin on a daily basis. So based on what these verses tell me, I have yet to be reborn. It is my understanding that if you sin everyday, then you're living in sin. How do you reconcile "I still sin" with the verses above?
Sadly, we are pinning Scripture against Scripture here, but context is everything!