Why does the Body of Christ have nothing to do with the tribulation?
The Body of Christ has nothing to do with the tribulation because it is not part of the Old Testament program. The tribulation is tied to the Old Testament and pertains primarily to the Jew. The Body is insulated from God's dealings with Israel before or after, and must be raptured before God resumes dealing with Israel.
Les explains that after Israel crucified their Messiah and Peter did not succeed in turning Israel to repentance, God brought up the Apostle Paul and began calling out the Body of Christ, primarily from among the Gentiles. Because this calling has nothing to do with the Old Testament program, it also 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. Les teaches the Rapture because the Body must be off the scene before God can pick up dealing with Israel again. If the Church were removed, the sequence returns to the Old Testament economy: the coming of the Messiah, the tribulation, the King, and the Kingdom. After Israel rejected it, God went to the calling out of the Body; it must be raptured, and then He will yet bring in the tribulation to Israel.