How long is the period of time from Paul's Gentile ministry until the Church is taken out?

Les explains that after Israel would not believe and receive her King, God raised up Paul and made known that he was going to the Gentiles. That opened the Age of Grace, the Church Age. Paul first goes to the Jew, but then to the Gentile, and that was the whole period of Acts until Paul takes over. From the time Paul began ministering to the Gentiles with the Gospel of Grace, Les says, there is this undetermined period of time. We do not know how long it will last; it has now come 1900 and some years. Then the Church will have to be taken out of the way so God can pick up where He left off with Israel, because that belongs back in the prophetic program. After the Tribulation, Christ will return, set up His Kingdom, and the raptured will come back with Him, as Les thinks, to rule and reign with Him. Chronologically, Paul does most of his ministry among the Gentiles and establishes churches from about 40 A.D. until he is a prisoner in Rome in about 65, and from about 58-59 he starts writing his letters.