What I Think Predestination Meant in Paul's Mind

I think one of the main points Paul was making, by speaking of 'predestination', was that this idea that the true people of God were identified simply by their faith in Jesus (regardless of ethnicity, and without them needing to become proselytes to Judaism), was an idea which had been genuinely thought of by God in advance, promised by God in the Scriptures long ago, and which had now been faithfully fulfilled by God, it wasn't something completely unheard of, without any basis at all in Old Testament Scriptures; and therefore those people who were believing, truly were the very community of people who were foreknown, foreseen, foretold, called, justified, and predestined for glory; and therefore they could rest fully assured in God's grace - even despite their detractors and present sufferings!

The mood of the term was celebratory in its reassurance - with a hint of polemic.