- See sin for the mathematical function.
A sin is an immoral act or omission considered by Christianity and some other religions to be wrong, against divine law, or offending God. It is used more widely to refer to immoral acts, but the origin comes from the story of the Fall in the Book of Genesis. Within Christianity, there are many different teachings about sin - the idea of original sin, the difference between venial sin and mortal sin, the idea stemming from liberation theology and others of social sin and the idea of the unforgivable or eternal sin. For Christians, Jesus Christ is generally held to have atoned for sin, both original and personal.