Today one of the chief spokesmen for the Reformed view is Dr. R.C. Sproul and his following statement correctly marks the major difference between Calvinism and other Christian belief systems:
"When someone mentions the term 'Calvinism,' the customary response is, 'Oh, you mean the doctrine of predestination?' This identification of Calvinism with predestination is as strange as it is real and widespread...In summary we may define 'predestination' broadly as follows: From all eternity God decided to save some members of the human race and to let the rest of the human race perish. God made a choice--he chose some individuals to be saved unto everlasting blessedness in heaven, and he chose others to pass over, allowing them to suffer the consequences of their sins, eternal punishment in hell" [emphasis added] (R.C. Sproul, What is Reformed Theology?[Grand Rapids: Baker Books, 2005], 141).
When we look at the following passage we can see that the "called" are believers (them that love God) and it is those who are already believe who are predestined:
"And we know that all things work together for good to them that love God, to them who are the called according to his purpose. For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren" (Ro.8:28-29).
The key to the teaching of this passage depends on an understanding of the meaning of the Greek word translated "for" found at the beginning of verse twenty-nine. The word is a conjuction which ties the two verses together, and the word means "the reason why anything is said to be or be done..it is added to a speaker's words to show what ground he gives for his opinion" (Thayer's Greek English Lexicon).
Here is another translation which makes the meaning even more clear:
"And we know that all things work together for good for those who love God, who are called according to his purpose, because those whom he foreknew he also predestined to be conformed to the image of his Son, that his Son would be the firstborn among many brothers and sisters" (Ro.8:28-29; NET).
At Romans 8:29 Paul tells us why he says that "all things work together for good" for the saved, those he describes as the called: "because those whom he foreknew he also predestined to be conformed to the image of his Son."
The reason why "all things work together for good" in regard to the saved is because the saved are predestined to be conformed to the image of the Son. That will happen when the Lord descends from heaven and the saved will put on bodies just like his glorious body:
"But our citizenship is in heaven. And we eagerly await a Savior from there, the Lord Jesus Christ, who, by the power that enables him to bring everything under his control, will transform our lowly bodies so that they will be like his glorious body" (Phil.3:20-21; NIV).
Now let us look at the verse which follows Romans 8:28-29:
"Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified" (Ro.8:30).
It is those who are already saved who are predestined, and the saved are called by the gospel. And the saved are also justified and glorified. So nothing in this verse contradicts the idea that it is the saved who are predestined to be conformed to the image of the Son.
The following verse is also speaking of the same destiny of those who are already saved:
"Having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will" (Eph.1:5; NKJV).
That is the same "adoption" that is in regard to the redemption of the body:
"And not only they, but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body" (Ro.8:23).
The following verse is also referring to the same exact thing:
"In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will" (Eph.1:11).
Just two verses later we learn more about this inheritance" to which the saved of this present dispensation have been ordained:
"In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, Which is the earnest of our inheritance until the redemption of the purchased possession" (Eph.1:13-14).
The redemption of the purchased possession will happen on the day of redemption and the purchased possession is our new, glorious body:
"And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption...the redemption of our body" (Eph.4:30; Ro.8:23).
So we can understand that the verses which use the word "predestinate" in regard to a person's destiny are not speaking of anyone being predestinated to salvation.