What prompts Paul to hark back again and again to the divine purpose is not an abstract predestinarianism or reference back to God’s decrees as the final cause in the chain of events, but the designation of sovereign, divine grace as the sole motive of his work of redemption in history.

One can raise the question as to whether after all the idea has not hereby been given of a predestined closed number of the elect and whether with that — even though not said in so many words— those who do not belong to this closed number have not been excluded in virtue of this same purpose before the foundation of the world.

One can only say of these questions that they place Paul’s pronouncements concerning the church as foreknown by God and elect in Christ under another point of view than that of Paul himself and thus abstract and extrapolate them from the context of the Pauline doctrine of salvation, an extrapolation that easily leads to conclusions Paul himself does not draw and which are entirely in conflict with the tenor of his preaching.

Herman Ridderbos, Paul: An Outline of His Theology