Original sin is a spiritual blindness, a corruption of the human soul and mind.
It is the source of all other sin in our persons. This inbred sinfulness is a deadly, spiritual disease we could never diagnose, understand or escape - apart from the grace of God. The Bible chronicles the beginning of sin in Genesis 3. God's perfect creation was ruined by the rebellious disobedience of the first man and woman. They and their descendants became subject to corruption and death in both body and soul.