Can God's dealings with Israel be brought into the Church, the Body of Christ?
No. God's dealings with Israel and His dealings with the Church, the Body of Christ, are two separate economies that cannot be mixed. You cannot take what God was doing with Israel and bring it into the Church which is His Body; they must be kept sorted and distinct.
Les teaches that in all his years of teaching, the key is to separate God's dealing with the Old Testament economy from His dealing with the Church. You cannot mix them; you have to keep them sorted. Israel and the Church are two separate economies. An economy is a system that makes something go. In the economies of God, you cannot take that which He was doing with Israel and bring it into the Church which is His Body. Nor can you jump ahead and put the tribulation saints back in the Body. Les also notes that Israel will never disappear because it has to be there for biblical prophecy to be fulfilled.