Which of Paul's letters contain his greater, later revelation?
Paul's greater, later revelation is contained in his prison epistles—Ephesians, Colossians, and Timothy. These later writings, toward the end of his career, set forth a greater revelation than his earlier pre-prison letters, Romans and Corinthians, which contain revelations he received earlier.
Les teaches that Paul had a progressive revelation, even as the Bible as a whole does. Some things come out in greater detail in Paul's later prison epistles than in the first one. Romans and Corinthians were the pre-prison epistles, the revelations Paul got early on. But when you get into Ephesians, Colossians, and Timothy, toward the end of his writing career, he has a greater revelation than he had back earlier. In Ephesians 1:9-10, Paul speaks of the mystery now revealed—God's purpose to gather together in one all things in Christ, both in heaven and on earth—and this is the hope of the believer.