What did the early church depend on before the New Testament was written?
Before any New Testament was written, early apostolic churches depended on gifted men—particularly those with the gift of prophecy—to proclaim and teach the Word of God, especially Pauline doctrine, without benefit of written Scripture. Their growth in the pagan world relied on such gifted proclaimers rather than a printed text.
Les explains that when Paul wrote to the Corinthians, there was still no New Testament written. The Gospels had not been written and would not be written until many years after Paul's letters, and his own letters had not yet gone out as the Word of God. So these early, primitive, apostolic churches were growing and reaching out in the pagan world without the benefit of the written Word. Les says they had to depend on gifted men, men gifted to teach people the Pauline doctrines and proclaim the truth of God's Word without having it in print. Paul, by inspiration, realized this was the most important thing the local church could have. Later, as Paul said in chapter 13, that gift would fade away because now we have the printed page, so men gifted to proclaim the Word without anything to go on are no longer needed.