What is the sequence: Israel's rejection, the calling out of the Body of Christ, the Rapture, and then the tribulation?
After Israel rejected Messiah and Peter's call to repentance failed, God raised up Paul to call out the Body of Christ, mainly from Gentiles. That Body is insulated from Israel's program and must be raptured before God resumes dealing with Israel, bringing the tribulation upon them.
Les explains that after Israel crucified their Messiah, Peter did not succeed in turning Israel to repentance. So God brought up the Apostle Paul and began calling out the Body of Christ, primarily from among the Gentiles. This calling has nothing to do with the Old Testament program, so it has nothing to do with the tribulation, which is tied to the Old Testament and primarily for the Jew. The Body of Christ is therefore insulated from God's dealings with Israel either before or after. That is why Les teaches the Rapture: the Body of Christ must be off the scene before God can pick up dealing with Israel again. If the Church is removed, the Old Testament economy resumes—Messiah's coming, the tribulation, the King, and the Kingdom. When Israel rejected, God went to the calling out of the Body of Christ, which has to be raptured, and then He will yet bring in the tribulation to Israel. Les points to Romans 11:25 as the triggering mechanism for Christ's coming for the Church, though no time element is known.