As we know, names are very individual. There are specific names written in the Lamb’s Book of Life, and this says they are written from the foundation of the world. This indicates that when Paul says we are predestined to adoption and predestined according to God’s purpose, he isn’t just talking about the church as a group. There are specific names written.
Again, our minds are so limited that it is hard to conceive of a Mind that can predetermine things thousands of years in advance. But just as an example, think about what God did with Cyrus, which is found in Isaiah 44—45. God named Cyrus approximately 140 years in advance and prophesied what he would do—and it came to pass. Now, if God knew Cyrus’ name at least 140 years in advance, there is nothing to stop the Almighty from knowing his name 150 years in advance, or 200 years in advance, and so on.
There is no point at which God can know a name this many years in advance, but one more year would be too much for Him. As we saw, He declares the end from the beginning. If He has purposed it, He will also do it. God demonstrated His foreknowledge with Cyrus, and there is no scriptural explanation for why He could not also choose some from the foundation of the world and write their names in His Book. He works all things according to the counsel of His will, and His foreknowledge is beyond our comprehension.