The foundation of Dispensational Futurism is the reasoning that true Israel is literal Israel. This view has major implications in eschatology because it would then have to be true that Israel will be saved in a corporate sense. Although everyone will agree that MANY Jews will be saved through faith in Christ, that does not imply that literal Israel will be saved corporately during the end.
This Dispensational view is also the root of all believes that the Temple in Jerusalem has to be rebuilt during the “tribulation” before the supposed rapture can occur. By correcting this view on who Israel is, many other false ideas will by default be eliminate.