Why do some things in Paul's letters come out in greater detail in his later epistles?

Paul experienced progressive revelation, just as Scripture as a whole unfolds progressively. What he received earlier in pre-prison letters like Romans and Corinthians is expanded in later prison epistles such as Ephesians, Colossians, and Timothy, where he had a greater revelation toward the end of his writing career.

Les teaches that Paul had a progressive revelation even as the Bible as a whole does. He points out that some things come out in greater detail in Paul's later prison epistles than in his first one. Romans and Corinthians were the pre-prison epistles, containing revelations Paul received early on. By contrast, Ephesians, Colossians, and Timothy were written toward the end of his writing career, where he had a greater revelation than he had back in those earlier letters. Les urges believers never to lose sight of this when studying Paul. The context also notes that the mystery of the believer's change was revealed to this apostle, and Ephesians 1:9 speaks of the secret of God's will being made known.

Are Paul's later letters more detailed than his earlier ones?

Yes. Paul's later prison epistles—Ephesians, Colossians, and Timothy—set forth certain truths in greater detail than his earlier letters, such as Romans and Corinthians. His writings reflect a progressive revelation, with later epistles containing a fuller revelation than the early ones.