If one was completely sinless, I'd think that he would be changed from mortal to immortal. Then the world would flock to him for all needs.
To me the greatest lie about this is not needing the body of Christ. It's making one the head, and not a member.
And I believe it's not sins as we normally define them, but faults of being human. Like quick in getting angry. Some are more sensitive to these things then others, and we are instructed to cover one then.
In posting all these warnings rather than the promises that build ones faith, it seems to me that these are accusations rather than a help and answers to a need.
They must believe we all are secret boozers, fornicators, committing adultery right and left.