 All of the priestly ritual focuses on Yahweh and the construction and maintenance of a holy space, but sin generates impurity, as do everyday events such as childbirth and menstruation; impurity pollutes the holy dwelling place.Failure to ritually purify the sacred space could result in God leaving, which would be disastrous.Through sacrifice, the priest "makes atonement" for sin and the offerer receives forgiveness (but only if God accepts the sacrifice—forgiveness comes only from God).