If a Christian believes that he has been cleansed of all sin and therefore does not have sin, is he not in the same boat as the gnostic who believes that he has no sin?
The Gnostic is going to hell.
The Believer is not.
Why?
Because the Gnostic does not BELIEVE they have sin that needs to be redeemed by the Blood of Jesus, so, they die : "You shall die IN YOUR SINs", as Jesus said.
See, someone is going to pay for those sins.
You will or Jesus has.
But not both.
Whereas, the Believer, who has received God's Righteousness and Christ has become their sin, has admitted they had sin, and has agreed with God that they need to be saved, and so, that is not the gnosic idea, at all.
This is not complicated, justbyfaith.
But for some reason, it is for you
So, your issue is one of 2 things.
You ither cannot understand, or your teacher who taught you was so bad, was so incorrect, that you have become mentally locked into their false teaching the same way youi became trapped in Hebrews, and can't get out.