It is essential that error be not confused with sin, and it is this distinction that makes salvation possible. For error can be corrected, and the wrong made right. But sin, were it possible, would be irreversible. The belief in sin is necessarily based on the firm conviction that minds, not bodies, can attack. And thus the mind is guilty, and will forever so remain unless a mind not part of it can give it absolution. Sin calls for punishment as error for correction, and the belief that punishment is correction is clearly insane.
Sin is not an error, for sin entails an arrogance which the idea of error lacks. To sin would be to violate reality, and to succeed. Sin is the proclamation that attack is real and guilt is justified. Sin is the grand illusion underlying all the ego's grandiosity.
A Course in Miracles http://acim.home.att.net/text-19-02.html