What did Paul not want the Gentile believers to be ignorant of?
Paul did not want Gentile believers ignorant of the mystery, or secret, that God had kept hidden in His own mind until He revealed it to Paul. The Greek word is mysterion, meaning secret. This mystery is central to Paul's drive that believers be well-taught.
Les explains that Paul does not want believers to be untaught. He says the church has failed miserably by not teaching its people, and that the average Roman Catholic, Episcopalian, Baptist, or Methodist often cannot tell you what they really believe, because nobody teaches them. So Paul is driving home that believers are to be a well-taught people, well read in the Scriptures. In this statement Paul says, I would not brethren, that you should be ignorant of this... Mystery. Les stresses that this word is one Paul uses often, and in Greek it is mysterion, meaning secret; a mystery or a secret. What Paul says is that he does not want the Gentile believers ignorant of a secret that God had kept in His own mind until He revealed it to the Apostle Paul. Les says he is stopping at this word because it has been quite a while since he stressed it.