How did Paul come to know the mystery of Christ?

Les explains that revelation means an unveiling—something kept under wraps is suddenly unveiled. Paul says that by revelation the Lord made known unto him the mystery, the secret, as he wrote before in a few words, so that when read, you may understand his knowledge in the mysteries of Christ. This mystery in other ages was not made known unto the sons of men as it is now revealed, specifically that the Gentiles should come in under God's grace. Verse 9 says this was to make all see the fellowship of this mystery, which from the beginning of the world, from Adam, had been hid, veiled, covered up, in God, the same God who created everything through Jesus Christ. There was a time when no one knew these things.