I suppose this will all come down to what can be derived by the term "foreknowledge". Does He know because He Himself caused it (His omnipotence and sovereignty), or does He know because of His omniscience and He knows whosoever will and whosoever won't?
Just to make it clear for those who may be new, I am not saying that we save ourselves.
That's enough for now. I await your response. I want to try to keep it simple.
There is a lot of exegetical conflict over "foreknow", because "foreknow [someone]" is not a well-used term in Greek. There are few examples. Far more prevalent is "foreknow [something]" or "foreknow about [someone]". This assures the meaning of prescience, with no regard to causation.
But Calvinism also doesn't apply "foreknow" as being "fore-cause", either. Calvinism essentially asserts "foreknow" is used as "know -- intimately or relationally -- beforehand". In other words, this isn't "knowing something about [someone]", this is "already relating to [someone] in love and grace".
We're always forced to talk through God's omniscience or omnipotence, as if that predestines people. But that's not the crucial point in Calvinism. Predestination is through God's Personhood -- because
that's His means of predestining people: through His own Personal actions -- Grace, Love, Mercy -- and even our own personal regeneration, faith, and receipt of God's Spirit Himself. That Personhood is the
crucial difference in Calvinistic predestination. That sets it apart from all else.
In debate we're constantly forced into explaining God's Power in talking about predestination.
But that's not the Calvinistic focus. We're dealing with an intense, intimate Person. And that's
Who brings about an intense, intimate personal predestination for those He is already in love with, is already shedding mercy on, is already bringing about change to.