In order to understand Calvinist teaching on predestination, it is important to look at the passages they favor. I would like to point out a couple of things that contrast their teaching, not to convince you of either side, but rather to balance your understanding so that you can choose for yourself, without bias what to believe. Scripture does talk about predestination, and the following passages are those that even use the word.
- Romans 8:29 For those God foreknew he also predestined to be conformed to the image of his Son, that he might be the firstborn among many brothers and sisters.
What the calvinist teaches here is that God foreknew, thus it is out of our hands, however, notice what we are predestined to...to being conformed to the image of His Son....Therefore, there are two sides, one side says God chooses, the other side says, God chose that we should be conformed to His image.
- Romans 8:30 And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.
Again, for the Calvinist, this means that only God chooses whom to save, but compare this passage to
Acts 14:17
Nevertheless he left not himself without witness, in that he did good, and gave us rain from heaven, and fruitful seasons, filling our hearts with food and gladness. or this one...
Romans 1:20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse:
- Ephesians 1:5 he predestined us for adoption to sonship through Jesus Christ, in accordance with his pleasure and will—
again, the Calvinist uses this passage to suggest that it is God who chooses who is to be adopted, but when we add passages like John 3:16 and Isaiah 53, we see that God's will is that all would come to the adoption as sons, through Jesus Christ...iow's the non Calvinist mindset, sees this passage the same way he sees
2 Peter 3:9
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward,
not willing that any should perish, but that all should come to repentance....that it is more about what Christ came to do, then it is about if and who God chooses to let into His glory.
- Ephesians 1:11 In him we were also chosen, having been predestined according to the plan of him who works out everything in conformity with the purpose of his will,
Here we have a repeat of the passage above, but we add to it, the idea of will...since God says that His will remains unchanged, the Calvinist dismisses the II Peter passage as it applies to this passage, that is not to say they struck it from their bibles (before anyone shoots me) but rather that they do not see this passage and the II Peter passage side by side in their thinking.
we could throw in a few other passages, but these are the hot button one's so to speak...so the next question as I understand your post, then is, where do they get this idea of a specific number of people are chosen...consider these verses...
Romans 11:25-26
25 I do not want you to be ignorant of this mystery, brothers and sisters, so that you may not be conceited: Israel has experienced a hardening in part until the full number of the Gentiles has come in, 26 and in this way[
a] all Israel will be saved. As it is written:
“The deliverer will come from Zion;
he will turn godlessness away from Jacob.
Revelation 6:11
Then each of them was given a white robe, and they were told to wait a little longer, until the full
number of their fellow servants, their brothers and sisters, were killed just as they had been.
Both talk about a specific number...for the Calvinist mindset, this is a confirmation that God chooses, for the other mindset, it is a confirmation that God already knows how many will choose Him. It's about God being all knowing, rather than about God not giving us choice.
Hope that helps