It's sad to see Paul locked in a death-struggle with the demon of sin. Jesus never talks about sin that way, in the authentic passages. Sin and guilt are such terribly inefficient concepts in spiritual practice: mostly dead weight, excrescences of the image of God as a harsh father. It is much simpler to see things done shoddily or harmfully as mistakes, grave mistakes perhaps, but actions arising out of our ignorance, greed, and hatred, and correctable, transformable, with enough sincere effort. The original meaning of to sin in Hebrew is "to miss the mark"; it has nothing metaphysical about it. And the sins I commit against others ultimately derive from the sin I commit against myself: I think myself down into a petty, unworthy, miserable creature and lose sight of my original magnificence. As for a sin against God, there is no such thing. Do the clouds sin against the sunlight?
Stephen Mitchell - The Gospel According to Jesus
(What is sin?)
The various traditions give many answers to this question, but they all essentially come down to this: I cannot perceive my own true identity, or my union with Spirit, because my awareness is clouded and obstructed by a certain activity that I am now engaged in. And that activity, although known by many different names, is simply the activity of contracting and focusing awareness on my individual self or personal ego. My awareness is not open, relaxed, and God-centered, it is closed, contracted, and self-centered. And precisely because I am identified with the self-contraction to the exclusion of everything else, I can't find or discover my prior identity, my true identity, with the All. My individual nature, "the natural man," is thus fallen, or lives in sin and separation and alienation from Spirit and from the rest of the world. I am set apart and isolated from the world "out there," which I perceive as if it were entirely external and alien and hostile to my own being. And as for my own being itself, it certainly does not seem to be one with the All, one with everything that exists, one with infinite spirit; rather, it seems completely boxed up and imprisoned in this isolated wall of mortal flesh.
TKW: "This situation is often called dualism, isn't it?"
KW: Yes, that's right. I split myself as "subject" apart from the world of "objects" out there, and then based upon this original dualism, I continue to split the world into all sorts of conflicting opposites: pleasure versus pain, good versus evil, true versus false, and so on. And according to the perennial philosophy, awareness dominated by the self-contradiction, by the subject/object dualism, cannot perceive reality as it is, reality in its wholeness, reality as the Supreme Identity. Sin, in other words, is the self-contraction, the separate-self sense, the ego. Sin is not something the self does, it is something the self is.
Ken Wilber - Grace and Grit