And it came to pass after these things, that God did tempt Abraham, and said unto him, Abraham: and he said, Behold, here I am.
And he said, Take now thy son, thine only son Isaac, whom thou lovest, and get thee into the land of Moriah; and offer him there for a burnt offering upon one of the mountains which I will tell thee of.
And Abraham stretched forth his hand, and took the knife to slay his son.
And the angel of the Lord called unto him out of heaven, and said, Abraham, Abraham: and he said, Here am I.
And he said, Lay not thine hand upon the lad, neither do thou any thing unto him: for now I know that thou fearest God, seeing thou hast not withheld thy son, thine only son from me.
And Abraham stretched forth his hand, and took the knife to slay his son
Lay not thine hand upon the lad, neither do thou any thing unto him
Evidently, Abraham was not going to sacrifice his son, no matter whether he chose to follow God’s direction or not. God was going to intervene, and thus funnel Abraham’s life back to the other branch regardless.
But would we say that Abraham did not have any agency in this matter? Did he not still make a decision, and in so doing permanently change something within himself? Though the outcome was the same either way, the exercise still mattered, if only on an internal level.
It is true that foreknowledge would destroy free will, but only if it were held in the same being that was making the choices. If that foreknowledge belongs to a separate being, such as God, than the other may still choose freely.
Consider the example of a game show. Does the fact that the game’s creators already know which prize is behind which door negate the player’s choice between them? Certainly not.