Freddie Knapp wrote, "Most of the Church fathers (for example Iraeneus and Clement) were known heretics. (...) The church was corrupt in Paul's day, so appealing to what a heretic believed in 150 AD is really weightless."
Great quote. Many of the oldest Christians who immediately followed Paul are great Christians and deserve our attention, but they're still human and fallible. And as Freddie pointed out, even those in Paul's time were corrupt.
Follow the church fathers as far as they followed Christ, no further.