From How Can God Answer Prayer:

3. Suppose we accept the third explanation: the explanation which affirms that God’s foreknowledge and foreordination are not necessarily all-comprehending.

You shrink from an attitude of thought like that toward the Supreme Being. It appears, does it not, to reflect discredit upon His perfection? Yet, let us not be too hasty in our judgment. Many earnest and noted scholars defend the position and strenuously maintain that not only does it not dishonor God, but that it is the only scheme of thought which does not divest Him of the essential attributes of His divinity.