uf you mean the antichrist he has not yet been revealed and when he does come that will in fact involve Israel so no the falling away would not be for the church, you said the verses you posted addressed the believers in Christ but it nowhere mentions that no who just the what and aside from the son of perdition the falling away could only be Israel because he will lead astray many yes but if you notice he makes a certain deal with Israel and is heavily involved in rebuilding the third temple only to proclaim himself God.
So again it seems the falling away must be with Israel not the believers in Christ
So again it seems the falling away must be with Israel not the believers in Christ