Nobody will be sinless this side of heaven.
I hope I dont know whats coming next, I hope that what is coming next is not equivocating sins unto death to sins not unto death. Such a biblical distinction exists, in both testaments too:
Numbers 15:28-30 1 John 5:16 & many others.
This will probably be just me using up the skin on my fingers by typing this, but I will still give an illustration in case you or someone else reading havent heard of this before, but I suspect you already have:
Stubbing your toe and letting out a curse word is not sinning willfully, or unto death as John says. But planning a robbery IS a sin unto death and willful. Its a heinous act that takes a lot of time to plan so its not just done accidentally.
There is that difference. But I know that eternal security believers often reject all such biblical distinctions to hold on to their doctrine. They quote James that says broke one law broke them all, while ignoring the other verses.
All James is saying is that you only need to violate the law of God once to be considered a "law breaker" and under the curse of the law. from which Jesus came to set us free from