the complete absence of any such notion in the Pauline corpus (or, for that matter, in John’s gospel, or in the other New Testament epistles, or in the earliest Christian documents of the post-apostolic church, such as the Didache and the writings of the “Apostolic Fathers,” and so forth)
Paul did earn a lot of opposition from other early Christians but their debates are not anywhere about whether the Gentiles will ultimately be saved; their debates are mostly about food, ie, about whether the Gentiles should be invited to the covenant and table right now.
