What was Paul being prepared to do according to this overview?

Les explains that this section is just an overview of Paul getting to the place where the Lord could use him to start calling out that next great body of resurrection—the Body of Christ, the Church. The mystery, the whole circle of Paul's doctrines, had been kept secret since the world began until God revealed them to this man. Les suggests much of it came out during the three years at Sinai, and the deeper revelations came out in Ephesians; he also notes the Lord may have poured out these deeper doctrines while Paul was sitting in prison in Caesarea waiting to go to Rome. Ephesians 3 shows how it came, and Les says Paul is the part of the Bible to read because this is where it is for the church age.