Jesus was the place of the overlap of heaven and earth (which is also the ancient understanding of the Temple---the place where God’s existence invaded the place of man’s existence), and this was evidenced by His constant defeat of the forces that stood in opposition to God and God’s purposes (healings, exorcisms, raising the dead, etc…). The responsibility to be the place of that heaven/earth overlap was that which Israel was charged to uphold, but did not. Jesus embodied Israel and succeeded where there had been failure, and this charge has been passed along to those that identify themselves as part of God’s family by Jesus’ name (affirming allegiance to Him, His kingdom, and the tenets of His kingdom program---bearing the covenant marker of belief in Him).
Paul expects nothing less than that the believing community model Jesus in succeeding in being the Israel of God, writing “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” (8:29). This is not about some foreordained calling of some percentage of the human population, such that some go to heaven and the rest go to hell. This is simply not in view, especially as we consider that such thinking was foreign to Paul’s worldview. It undoubtedly is the case that not all will embrace Jesus and acknowledge the Creator God through Him, so there is a group of people that will participate in the kingdom of God during their lives while others do not. That said, the passage is not intended to convey information about the final destination of a human soul.
Again, if we trace the context of the passage, its connection to the exodus of Israel, and its placement within the whole of the letter that seems to have to do primarily with the family of God and its representation of the kingdom of God in and for the world, we realize that thoughts about predestination, in the sense of determining “who’s in and who’s out,” are simply not on the field. Once we put that out of the way, what we see---and this seems to be far more appropriate---is that the passage is about the covenant faithfulness of the Creator God, that faithfulness that is recorded in the narrative of Israel that runs back to the story of Adam, and the impetus for the unified covenant family that is composed of all peoples to take up its role. The passage is about what God is going to do for His creation, how He has been doing it, how He is going to do it, and about the people of the covenant getting on board with and participating in that plan.
God had called Israel His son---His firstborn. Israel, the groaning people of Egypt (we can’t forget our groaning context), was foreknown by God as evidenced by the promise to Abraham about His people that would go into captivity and then come out of captivity. The foreknowing of God demands to be understood in accordance with the story of Israel. God’s intention for Israel, whose story and purpose is predicated by God’s interactions with Abraham, was to set the world to rights, reversing the failure of Adam, who was looked upon as the son of God, created in His image, given a covenant responsibility, and failed. Thus, Israel, whom God foreknew (as established by the narrative that includes promises and prophecies to Abraham), was predestined (purposed) to succeed where Adam had failed.
Jesus, who pieced together the messianic mission from His understanding of Israel’s story, along with the wisdom and prophetic literature, thus establishing the idea of foreknowing and predestination for Him as well, succeeded where both Israel and Adam had failed. So the foreknowing of God in regards to Jesus also demands to be understood in accordance with the story of Israel. The same can also be said for the church whose mission is foretold and purposed by the Jesus-centered-and-shaped messianic tale, and which is now tasked with announcing and carrying on the successes and even the seeming failure of Jesus.
Here, we remember that crucifixion was a mark of decided failure. However, the Resurrection reverses the seeming failure, making it possible to understand the cross as the place where Israel’s full cursing (Leviticus 26 and Deuteronomy 28) is carried out against Jesus as embodied Israel. Accordingly, the Resurrection tells the covenant community that embracing the cross, which will mean going to the place of willful experience of suffering and shame (mimicking Jesus in His “failure”) if it will advance God’s creation-and-humanity-redeeming kingdom program, and doing so on behalf of others so as to be the place of the coming together of heaven and earth and an announcement of the kingdom of God.
Thus, the church (the covenant people of God culled from all of humanity, not just ethnic or national Israel, who bear the covenant marker of belief in Jesus), whom God ultimately foreknew in Abraham, was predestined to be conformed to the image of Jesus, reproducing a family of divine image-bearers. It is with this purpose clearly in mind that we then hear Paul say “And those He predestined, He also called; and those He called, He also justified; and those He justified, He also glorified” (8:30). Paul believes that according to the Scriptures (from Abraham through the prophets), God, as planned, is calling out a people from all nations (called), including them under His covenant banner through belief in Jesus (justified), and tasking them with reflecting His glory into the world (glorified).