Paul’s thought, which he apparently garnered at least in part from Isaiah, is that the people of national Israel of the Old Testament will not all be saved. Only a remnant of ethnic Israelites, those who try in the long run to follow God, rather than rebel against him, receive God’s promise of salvation. The idea is that a necessary aspect of salvation includes belief in God (which means a faithful following of his way). God excludes the persistently disobedient from his promises of blessing, comfort, and salvation. …