No one can "not sin". Saying that one does not sin calls God a liar. 1 John 1:8
"If we claim not to have sin, we are deceiving ourselves, and the truth is not in us."
The truth would be to say we are free from sin in Christ. That is the Atonement.
That is correct. Everyone who does not have Christ will sin and walk in darkness 1 John 1:6; sin is still in their nature. Also 1 John 1:10 So no matter how hard they try, they will still sin, if only in their heart. This is why the next verse is how to become a Christian. They are cleansed from ALL sin, and are no longer sinners but children of God. 1 John 3:1. Then 1 John 3:5 is the result.
I know most churches teach that because John uses the word "we" that all those in 1 John 1 are saved. But the chapter is one of contrasts from verse 5 through verse 10. It is chapter three that shows the difference between those who sin and those who don't. Many church-going sinners prefer to believe the lie, rather than repent and be free from their desire to sin. Only the truth will set us free. Read John 8:32-36
Matthew 7:14
Because narrow
is the gate and difficult
is the way which leads to life, and there are few who find it.
Before it is too late, repent and asked to be scrubbed clean. Ask for the gift of the Holy Spirit. If you are still sinning, believe me, you don't have Him. You
must be born again of the Spirit.