Certainly, since God knows everything, it would have been possible for God to base His predestination and election of individuals upon His foreknowledge of the future. In fact, that is the exact position that many Christians believe, as it is the Arminian view of predestination. The problem is that it really is not what the Bible teaches about predestination, election, and foreknowledge. In order to understand why the view that “God made His choice based on merely knowing the future” is not what the Bible teaches, let's first consider the passages that speak into the tension (but not irreconcilable tension) between predestination, election, and foreknowledge.
Ephesians 1:5 tells us that God “predestined us to be adopted as his sons through Jesus Christ, in accordance with his pleasure and will.” According to this verse, the basis of our being predestined is not something that we do or will do, but is based solely on God in accordance with His good will and pleasure.
In Ephesians 1:11 we see that people are “chosen, having been predestined according to the plan of him who works out everything in conformity with the purpose of his will.” From these and many other passages, we see that Scripture consistently teaches that predestination or election is not based upon something that we do or will do. God predestined people based on His own sovereign will to redeem for Himself people from every tribe, tongue, and nation. God predetermined or predestined this from before the foundation of the world (Ephesians 1:4) based solely on His sovereign will and not because of anything that He knew the people would do.
But what about Romans 8:29 where it says that those “He foreknew, He also predestined”? Doesn't that seem to say that predestination is based upon the foreknowledge of God? Of course, the answer is yes, it does teach that predestination is based on the foreknowledge of God. But God’s foreknowledge, or knowing things or events before they exist or happen, is not the only basis for predestination. We know that His will and pleasure are also involved. God foreknowing and predestining reveals His sovereignty, but we also learn in the Bible that people are accountable for their choices (Joshua 24:14-15, Luke 10:42, Hebrews 11:24-25). The issue really is not whether or not God knows who will believe, but why some believe and others do not. God’s desire is that all would be saved and come to repentance (1 Timothy 2:4, 2 Peter 3:9). He offers salvation to everyone (Titus 2:11), yet we know that not everyone will be saved.
The following quote by John Murray is excellent in dealing with this issue: “Even if it were granted that “foreknew” means the foresight of faith, the biblical doctrine of sovereign election is not thereby eliminated or disproven. For it is certainly true that God foresees faith; He foresees all that comes to pass. The question would then simply be: whence proceeds this faith, which God foresees? And the only biblical answer is that the faith which God foresees is the faith He himself creates (cf. John 3:3-8; 6:44, 45, 65; Ephesians 2:8; Philippians. 1:29; 2 Peter 1:2). Hence His eternal foresight of faith is preconditioned by His decree to generate this faith in those whom He foresees as believing.”