The term sin comes from a Greek word that means to "miss the mark". It was used by archers who were in a contest trying to hit the bull's eye but who did not quite hit the innermost circle. Thus, they had sinned or missed the mark.
Normally when we see the word sin in the Bible it conveys the meaning that a person may be trying hard to hit the bull's eye of perfection but he just can't do it. We can all identify with the Apostle Paul who said in Romans 7 that he was trying to act perfectly but perfection eluded him. "I know what is right," he says, "but I just can't do it".
The Commandment Paul mentions as an example is Coveting. It is brilliant because it comes from the heart. I may be able to fool you into thinking I am not coveting your house, car or bling, but my heart knows better. That is missing the bull's eye.
Sin comes from having a fallen or distorted nature. It oozes out of me at the times I least expect it. I want to be better and do better but my nature fights me. Christianity is not about being better. My works are all filled with self deceit and selfishness. They are filthy rags because they arise from a sinful heart.
Some folks tell us to try harder. But Paul said it would not help. He cried out in anguish, "Who will deliver me from this body of flesh?"
Then he answers himself. "Praise God, through Jesus Christ."
Jesus paid it all
All to Him I owe
Sin had left a crimson stain
He washed it white as snow