The word ‘indulgence’ is a very familiar term of history, known ambiguously even by non-religious to be connected with the Church's ‘corrupt extortion of the poor so that they may pay for the forgiveness of sins and enter heaven’ as they imagine. This however, is far from true, for an indulgence does not forgive one's sin, nor can possibly do so since (as we see with the Jubilee indulgence) it takes place after the Sacrament of Penance by which a Catholic receives absolution for all his sins. I will demonstrate the true teaching of indulgences, it's biblical foundation, and it's foundation in Christian antiquity