So the early Church was reliable in telling us what were the books of the Bible but not in telling us what they meant?
'Scuse me, but in the beginning there was no "Church" as you term it. There were only churches, each with its own appointed elders of spiritually mature leaders (at first discipled Jews), and owing allegiance and dominion to no other entity than The Risen Christ and The Holy Ghost, Who is the Author of the Preserved Text.