Nicene and Post-Nicene Fathers: Series II/Volume III/Lives of Illustrious Men/Gennadius/Theodulus the presbyter

a presbyter in Coelesyria is said to have written many works, but the only one which has come to my hand, is the one which he composed On the harmony of divine Scripture, that is, the Scriptures of the Old and New Testaments, against the ancient heretics who on account of discrepancies in the injunctions of the ritual, say that the God of the Old Testament is different from the God of the New. In this work he shows it to have been by the dispensation of one and the same God, the author of both Scriptures, that one law should be given by Moses to those of old in a ritual of sacrifices and in judicial laws, and another to us through the presence of Christ in the holy mysteries and future promises, that they should not be considered different, but as dictated by one spirit and one author, since these things which if observed only according to the letter, would slay, if observed according to the spirit, would give life to the mind. This writer died three years since in the reign of Zeno.