Atonement in Christianity
Atonement is reconciliation with God, of people who have sinned . It is a concept of forgiveness and repair, based on the mercy of God, which is derived from Judaism, and became the central idea of Christian theology.
In Judaism, the Holiest day of the year is the Day of Atonement known as Yom Kippur in Hebrew. It comes exactlt ten days after the Jewish New Year known as Rosh Hashana.
See sin (major article) for more information.