A sin is an act that violates a known moral rule in a religion. The term sin may also refer to the state of having committed such a violation. Sin can refer not only to physical actions taken, but also to thoughts and internalized motivations and feelings. Colloquially, any thought, word, or act considered immoral, selfish, shameful, harmful, or alienating might be termed "sinful".
Common ideas surrounding sin in various religions include:
- Punishment for sins, from other people, from God either in life or in afterlife, or from the Universe in general.
- The question of whether an act must be intentional to be sinful.
- The idea that one's conscience should produce guilt for a conscious act of sin.
- A scheme for determining the seriousness of the sin and the importance of responsibility.
- Repentance from (expressing regret for and determining not to commit) sin, and atonement (repayment) for past deeds.
- The possibility of forgiveness of sins, often through communication with a deity or intermediary; in Christianity often referred to as salvation. Crime and justice are related secular concepts.