So overwhelming is the evidence for baptismal regeneration in the patristic literature that even critics of the doctrine are forced to admit it has the unanimous consent of all the patristic authors who commented on the issue. William Webster, a Reformed Protestant apologist, admits to such in his book, The Church of Rome at the Bar of History (Banner of Truth, 1995), 95-96.
In this lecture, David Bercot presents just some of the evidences for this doctrine in the Ante Nicene writings (those pre-dating 325 AD).
