The text amply demonstrates in chapter 44 and previous chapters that God does separate peoples. He distinguishes between those who receive the true words of his genuine prophets and those who follow the false narratives of their own hearts. In other words, God recognizes those who repent in truth (turn back to him, verse 22) against those who continue in their own ways with their backs turned away from God. Finally, God calls his faithful by the names Israel and Jerusalem. …
The “Barren”–Faithful Israel: Devotional 2.57
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. …