Interesting discussion! (Nonetheless, it's filled with mis-assumptions about Christian belief; moreover, it's pretty much a point-for-point rehash of Medieval Islamic Philsophy -- see, back then, Islamic philosophers were dealing with the implications of Ancient Greek philosophy, and had a hard time reconciling it with their belief in an omnipotent Allah. They, too, posited that, since God could do everything, that everything that happened wasn't really our own free will -- or even action -- but rather, just the act of a puppet.)
For example, one famous argument was that, since God was omnipotent, the idea that we actually act runs counter to that argument. Therefore, if we put a lit match up to some cotton, the resulting fire couldn't be anything that we caused, or else it would nullify God's omnipotence. Instead, there was just the illusion that the fire that we thought we initiated actually caused the fire in the cotton; rather, God simply put the fire there, ex nihilo, in order to keep up the illusion he created. You can see what this does to free will, and how it dovetails with your argument.
As another has noted in this thread, "God works through us" doesn't mean "God directs our actions"; rather, it simply means that we work, and in doing so -- out of our own volition -- we may do the will of God.
The implication is that, although God knows the result of the soccer game, he doesn't take any action to influence that outcome. He's outside of the space/time construct; therefore, for him, it's "preknowledge", although to us, it appears as "predestination".
Calvinists would disagree with this argument -- they would argue for strict predestination. However, to argue that this is what Christianity teaches -- or moreover, that this is what it implies -- is to make an overly broad and reaching assertion...
