"We do not build temples, and ordain priests, rites, and sacrifices for these same martyrs; for they are not our gods, but their God is our God. Certainly we honor their reliquaries, as the memorials of holy men of God who strove for the truth even to the death of their bodies, that the true religion might be made known, and false and fictitious religions exposed. For if there were some before them who thought that these religions were really false and fictitious, they were afraid to give expression to their convictions. But who ever heard a priest of the faithful, standing at an altar built for the honor and worship of God over the holy body of some martyr, say in the prayers, I offer to you a sacrifice, O Peter, or O Paul, or O Cyprian? For it is to God that sacrifices are offered at their tombs—the God who made them both men and martyrs, and associated them with holy angels in celestial honor; and the reason why we pay such honors to their memory is, that by so doing we may both give thanks to the true God for their victories, and, by recalling them afresh to remembrance, may stir ourselves up to imitate them by seeking to obtain like crowns and palms, calling to our help that same God on whom they called."
~St. Augustine: The City of God, Book 8, Chap. 27.