A tradition teaches that certain acts, thoughts, or states violate the divine will or the moral order of the universe. Those violations are sins. The concept structures religious ethics and the need for forgiveness or purification.

Sin may be understood as rebellion, ignorance, imbalance, or failure in relationship. Some systems emphasize individual culpability; others stress collective or structural dimensions. Distinctions between mortal and venial, or between intentional and unintentional, appear in various teachings. Confession, atonement, and repentance are ordinary responses.

The doctrine of sin diagnoses the human condition as more than mere imperfection. It also opens the possibility of restoration. Critics find the concept oppressive; practitioners find it realistic and ultimately hopeful. How a tradition defines sin largely determines how it understands salvation.

Sin names the gap between what is and what ought to be before the sacred.