Banyak pemimpin kristen awal juga menganut prinsip ajaran Sola Scriptura misalnya :
180 AD: Irenaeus:
"We have learned from none others the plan of our salvation, than from those through whom the Gospel has come down to us, which they did at one time proclaim in public, and, at a later period, by the will of God, handed down to us in the Scriptures, to be the ground and pillar of our faith. For it is unlawful to assert that they preached before they possessed "perfect knowledge," as some do even venture to say, boasting themselves as improvers of the apostles." (Irenaeus, Against Heresies, book 3, 1, 1)
Irenaeus states that the gospel was first orally revealed, then the gospel was recorded in scriptures and calls the scriptures the "ground and pillar" of faith. This should send shivers up the spine of every Roman Catholic and Orthodox because it is a clear interpretation of 1 Tim 3:15 where the same expression is used of the church. Obviously then, Irenaeus viewed that the church came second in authority under the scriptures. It is also clear that you can make no change from what the apostles teach as it was the unchangeable standard of doctrine.