It is impossible not to sin as long as we live in duality. Breathing is a sin - sin is not an act of some sort as is popularly believed. Sin is a conscious environment that is produced by "eating" from the tree that knows, judges and discerns good from evil.
The scripture says, "The strength of sin is THE LAW." (1 Corinthians 15:53b) This is difficult to comprehend because as egoist beings we are action oriented. We need to discern good from evil in order to survive in this environment. HOWEVER, Jesus told us mysteries on how to transcend the age - this mode of ascension is against the ego!
The ego must willingly "die" like the pattern of the cross, so that we might be made alive to a totally different mode of being. The ego surrenders its role as a master of being and instead becomes a servant of the Divine.
This action of the ego in subservience to the Divine will produce another environment.
Many people misunderstand the woman caught in adultery whom Jesus forgave and told to go "sin no more." The adulterous woman is us. It is the feminine aspect of humanity that has joined herself to many other lovers down throughout the ages. This is an admonition to stop intercourse with duality and enter into union as a bride yields to her groom. A mystery indeed.
Is scripture history? Yes. There very well may have been a woman caught in adultery. Is scripture mystery? Mystery? Absolutely. We must lift our eyes to see...