Romans 8:29

The apostle, having reckoned up so many ingredients of the happiness of true believers, comes here to represent the ground of them all, which he lays in predestination. These precious privileges are conveyed to us by the charter of the covenant, but they are founded in the counsel of God, which infallibly secures the event. That Jesus Christ, the purchaser, might not labour in vain, nor spend his strength and life for nought and in vain, there is a remnant given him, a seed that he shall see, so that the good pleasure of the Lord shall prosper in his hands. For the explication of this he here sets before us the order of the causes of our salvation, a golden chain, which cannot be broken. There are four links of it: - I. Whom he did foreknow he also did predestinate to be conformed to the image of his Son. All that God designed for glory and happiness as the end he decreed to grace and holiness as the way. Not, whom he did foreknow to be holy those he predestinated to be so. The counsels and decrees of God do not truckle to the frail and fickle will of men; no, God's foreknowledge of the saints is the same with that everlasting love wherewith he is said to have loved them, Jer 31:3. God's knowing his people is the same with his owning them, Psa 1:6; Joh 10:14; Ti2 2:19. See Rom 11:2.

— Matthew Henry's Concise Commentary (public domain)

For--as touching this "calling according to his purpose" (Rom 8:28). whom he did foreknow he also did predestinate--foreordain. In what sense are we to take the word "foreknow" here? "Those who He foreknew would repent and believe," say Pelagians of every age and every hue. But this is to thrust into the text what is contrary to the whole spirit, and even letter, of the apostle's teaching (see Rom 9:11; Ti2 1:9). In Rom 11:2, and Psa 1:6, God's "knowledge" of His people cannot be restricted to a mere foresight of future events, or acquaintance with what is passing here below. Does "whom He did foreknow," then, mean "whom He foreordained?" Scarcely, because both "foreknowledge" and "foreordination" are here mentioned, and the one as the cause of the other. It is difficult indeed for our limited minds to distinguish them as states of the Divine Mind towards men; especially since in Act 2:23 "the counsel" is put before "the foreknowledge of God," while in Pe1 1:2 "election" is said to be "according to the foreknowledge of God." But probably God's foreknowledge of His own people means His "peculiar, gracious, complacency in them," while His "predestinating" or "foreordaining" them signifies His fixed purpose, flowing from this, to "save them and call them with an holy calling" (Ti2 1:9). to be conformed to the image of his Son--that is, to be His sons after the pattern, model, or image of His Sonship in our nature.

— Jamieson-Fausset-Brown Commentary (public domain)