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.
This verse shows God’s ultimate purpose in working all things together for good (v.28). Our current verse is an elaboration on “those who are called according to His purpose.” The entire following section of Romans eight is a grand sweep of God’s plan. We will see five links in a chain that show succession and graduation—all God’s actions as He:
These five doctrines capture God’s design for believers beginning from the origin of God’s dealing with us to the culmination in our glorification. These five actions by God did not take place in succession but in one fell swoop from God’s viewpoint. From man’s viewpoint they are in logical succession.
29 For [reason, cause]
“For” is a term of explanation; it links verse 29 to verse 28. The “foreknow” in this passage links with the “know” of verse 28. The latter verse said God works “all things together for good” for believers and that He has a “purpose” in doing so. We “know” this. The “good” is not due to chance or luck but because God is sovereign. This is true from God’s foreknowledge to our glorification.
In verses 29 and 30 we have five verbs all with point action. These verbs (foreknew, predestined, called, justified, glorified) show how God carried out His purpose (v.28). Each of these terms occurred at one point in the past but logically they are sequential, each preparing the way for the next.
The “whom” here is exclusively Christians. No matter what trial may come the way of a Christian, nothing can hinder God’s plan for him or her.
God executed five certainties for believers by His plan.
The reason “all things work together for good” to Christians is that God has a plan that we can count on. All of this involves our “call” as Christians:
1 Co 1:9, God is faithful, by whom you were called into the fellowship of His Son, Jesus Christ our Lord.
Php 1:6, being confident of this very thing that He who has begun a good work in you will complete it until the day of Jesus Christ;
1 Th 5:24, He who calls you is faithful, who [God] also will do it.