Suppose there arise a dispute relative to some important question among us, should we not have recourse to the most ancient Churches with which the apostles held constant intercourse, and learn from them what is certain and clear in regard to the present question? For how should it be if the apostles themselves had not left us writings? Would it not be necessary, in that case, to follow the course of the tradition which they handed down to those to whom they did commit the Churches?
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 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 LyonsThrough a tree we were made debtors to God; so through a tree we have our debt canceled.
Irenaeus of LyonsThe Virgin Mary, being obedient to his word, received from an angel the glad tidings that she would bear God.
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 Lyons[Naaman] dipped himself," it says, "seven times in Jordan." It was not for nothing that Naaman of old, when suffering from leprosy, was purified upon his being baptized, but as an indication to us. For as we are lepers in sin, we are made clean by means of the sacred water and the invocation of the Lord from our old transgressions, being spiritually regenerated as new-born babes, even as the Lord has declared: "Except a man be born again through water and the Spirit, he shall not enter into the kingdom of heaven.
Irenaeus of Lyons