The cancelling by the Christian Church of the temporal punishment still owed for sins after they have been forgiven. The idea was found in various forms in the early Church, but as a widespread doctrine it dated from the 11th century, especially with the granting of indulgences to those who went on Crusades. They could be obtained by saying certain prayers or by performing specified good works, such as helping the needy, taking part in a Crusade, or giving money to churches. It was through the connection with money payments that indulgences were most open to abuse, and that they became a focus for criticism by Martin Luther and others during the Protestant Reformation.