Most Catholics know, at least intuitively when the collection basket is passed every Sunday, that they should give to the Church. What often remains unclear, however, is if there is a binding obligation to do so. Is giving to the Church like giving to a secular charity such as the Red Cross? And if Catholics have a duty to give, how much? Should they tithe (i.e., give 10% of their earnings) as Christians did in times past or rely on another metric altogether?