Against the Heresies 1 by Irenaeus of Lyons

Gnosticism* The doctrine of salvation by knowledge. This definition, based on the etymology of the word (gnosis knowledge, gnostikos, good at knowing), is correct as far as it goes, but it gives only one, though perhaps…

But one and the same householder produced both covenants, the Word of God, our Lord Jesus Christ, who spoke with Abraham and Moses, and who has again restored us to liberty and has multiplied that grace that is from hims…

2. Error, indeed, is never set forth in its naked deformity, lest, being thus exposed, it should at once be detected. But it is craftily decked out in an attractive dress, so as, by its outward form, to make it appear to…

To Gnosticism's separation of soul and body, spirit and flesh, pneumatic and animal existence, Christianity opposed the Incarnation of God. The fact that God has become man, indeed flesh, proves that the redemption and r…

St. Paul and St. John had begun the struggle against Gnosticism, which in their time was in its early stages. Even so, it was already showing its pernicious tendencies: promoting its seductive secret knowledge in the Chr…

Irenaeus taught the unity of the testaments in Christ: they were different, because they were different stages in the one divine education of the human race. In contrast to Gnosticism's cold presumption, he proclaimed Go…