When did God reveal the deeper doctrines of Paul's prison epistles?
The deeper doctrines of Paul's prison epistles were revealed while Paul was imprisoned in Caesarea awaiting his journey to Rome. The mystery kept secret since the world began was revealed to Paul, and these deeper revelations came out in Ephesians, likely poured out during that Caesarean imprisonment.
Les explains that the mystery, the whole circle of Paul's doctrines, was kept secret in the mind of God since the world began until God revealed them to Paul. Most of these doctrines came out during the three years at Sinai, but the deeper revelations appear in Ephesians. Les suggests the Lord may have poured out all these deeper doctrines while Paul was sitting in prison in Caesarea waiting to go to Rome. He then directs attention to Ephesians chapter 3, where these truths are unfolded.