29 For whom He foreknew, He also predestined to be conformed to the image of His Son, that He might be the firstborn among many brethren.
to be conformed
The word “conformed” enables us to understand predestination. The use of the adjective form (not a verb) gives great emphasis to the idea of being “conformed.” Christians will share in the destiny, righteousness, and glory of Jesus Christ.
The goal of God’s predetermination is conformation into the image of His Son. The “good” of verse 28 is achieved when God conforms believers into the likeness of Jesus. Christians participate in the image of the Son.
“Conformed” means to be brought into the same form with another person or thing. The believer is brought to an outward expression of the inward essence of the image of the Son of God. Sanctification is the process whereby God conforms the saint to resemble the Lord spiritually.
to the image [derived appearance] of His Son,
To be conformed into the “image of His Son” is ultimate and comprehensive sanctification, a sanctification that has the image of the Son. The “image” is a derived likeness to Jesus; it is not accidental.
God is committed to conforming us into the likeness of the glorified Son of God.
The image of Christ that God is conforming us to is like the image parents confer by genetics upon their children. Jesus will be glorified in us. God is in the business of transforming us into conformity to the finished product of His Son. This will happen at the believer’s resurrection and glorification (Co 1:15; 1 Co 15:49; Ph 3:21). We are made in the pattern of the Son.