For whom he did foreknow, he also did predestinate. — The process already summed up under these two phrases is now resolved more fully and exactly into its parts, with the inference suggested that to those who are under the divine guidance at every step in their career nothing can act but for good. The two phrases indicate two distinct steps. God, in His infinite foreknowledge, knew that certain persons would submit to be conformed to the image of His Son, and he predestined them for this.
When we argue deductively from the omniscience and omnipotence of God, human free-will seems to be obliterated. On the other hand, when we argue deductively from human free-will, the divine foreknowledge and power to determine action seem to be excluded. And yet both truths must be received without detriment to each other. We neither know strictly what God’s omnipotence and omniscience are (according to a more exact use of language, we ought to say, perhaps, “perfect power and knowledge” — power and knowledge such as would belong to what we are incapable of conceiving, a perfect Being), nor do we know what human free-will is in itself. It is a necessary postulate if there is to be any synthesis of human life at all; for without it there can be no distinction between good and bad at all. But we do not really know more than that it is that hypothetical faculty in man by virtue of which he is a responsible agent.
To be conformed... — The final cause of the whole of this divine process is that the Christian may be conformed to the image of Christ — that he may be like him not merely in spirit, but also in that glorified body, which is to be the copy of the Redeemer’s (Philippians 3:21), and so be a fit attendant upon Him in His Messianic kingdom.
Firstborn among many brethren. — The Messianic kingdom is here conceived of rather as a family. In this family Christ has the rights of primogeniture, but all Christians are His brethren; and the object of His mission and of the great scheme of salvation (in all its stages — foreknowledge, calling, justification, &c.) is to make men sufficiently like Him to be His brethren, and so to fill up the number of the Christian family. The word “firstborn” occurs in a similar connection in Colossians 1:15, “firstborn of every creature” (or rather, of all creation), and in Hebrews 1:6, “When he bringeth in the first-begotten (firstborn) into the world.” It implies two things — (1) priority in point of time, or in other words the pre-existence of the Son as the Divine Word; and (2) supremacy or sovereignty as the Messiah. The Messianic use of the word is based upon Psalms 89:27, “Also I will make him my first-born, higher than the kings of the earth.”
Among many brethren. — Comp. Hebrews 2:11 et seq., “He is not ashamed to call them brethren,” &c. There is a stress on “many.” The object of the Christian scheme is that Christ may not stand alone in the isolated glory of His pre-existence, but that He may be surrounded by a numerous brotherhood fashioned after His likeness as He is in the likeness of God.