Was the church a secret hidden in the mind of God until Paul?
Yes. The church, the body of Christ, was kept secret and hidden in the mind of God until it was revealed to Paul. It is not found in the Old Testament or the Gospels but is strictly a Pauline revelation of grace doctrine.
Les explains that all prophecy is directed to Israel, and no prophecy is being fulfilled today; the stage is merely being set. During the Acts transition, Saul was converted, and after three years of private training, God revealed the mysteries to Paul. These mysteries comprise the sphere of grace doctrine. Les emphasizes that nothing of the church or the body of Christ appears in the Old Testament or the Gospels; it is strictly a Pauline revelation, kept secret and hid in the mind of God until that time.