Did Paul receive all his revelation at once?
No, Paul did not receive all his revelation at once. His letters show a progressive unfolding: Romans and Corinthians contain earlier revelations, while Ephesians, Colossians, and Timothy reflect a greater later revelation toward the end of his writing career, just as Scripture as a whole also unfolds progressively.
Les teaches that Paul had a progressive revelation even as the Bible as a whole does. Some things come out in greater detail in his later prison epistles than they do in the first one. Romans and Corinthians were the pre-prison epistles, the revelations Paul got early on. But Ephesians, Colossians, and Timothy are toward the end of his writing career, where he has a greater revelation than he had back there. Les stresses never to lose sight of that when studying Paul. He then points to Ephesians 1:9, where Paul says the secret of God's will is now revealed, and calls it the hope of the believer.