The preaching of the Church truly continues without change and is everywhere the same. It has the testimony of the Prophets and Apostles and all their disciples.
Irenaeus of LyonsPrior to Valentinus, those who follow Valentinus had no existence. Nor did those from Marcion exist before Marcion. Nor, in short, did any of those malignant-minded people, whom I have listed above, have any existence previous to the initiators and inventors of their perversity.
Irenaeus of LyonsHe [Jesus] came to save all through himself; all, I say, who through him are reborn in God: infants, and children, and youths, and old men. Therefore he passed through every age, becoming an infant for infants, sanctifying infants; a child for children, sanctifying those who are of that age . . . [so that] he might be the perfect teacher in all things, perfect not only in respect to the setting forth of truth, perfect also in respect to relative age
Irenaeus of LyonsAnd when we come to refute them, we shall show in its fitting place that this class of men [i.e., the gnostics] has been instigated by satan to a denial of that baptism which is regeneration to God, and thus to a denial of the whole faith [by denying all physical aspects of spirituality, including the incarnatian and bodily resurrection of Jesus].
Irenaeus of Lyons