Almost every theologian agrees that God has some knowledge of future events, but what God actually knows and how He aquired that information has been debated for centuries.  Below are four basic models of foreknowledge based on the method God employs to get that knowledge.

1. Calvinism (His will) - The view of Augustine, Aquinas, Luther and Calvin was that God's foreknowledge is based on His will.  God determines all future events by His soveriegn will. These decrees then become His foreknowledge.  In this view, God is not changed by His creation.  None of His actions, choices, or knowledge are affected by creatures. God cannot change and cannot be changed.
2. Arminianism (His knowledge of His creation's choices) - Other thinkers such as Arminius thought that God foreknows the future by looking forward to see what actions His creatures will take.  His foreknowledge is based on His ability to see all future free-will actions.  He then is able to elect those whom He sees place their faith in Him.  This God is capable of changing His mind based on human action. (See Simple Foreknowledge)
3. Molonism (His choice of worlds) - Molonism envisions God, before time and creation, seeing all the possible worlds He could create and all the different choices humans might make based on His actions.  God chooses to create or actualize only one of these worlds by His choice and good pleasure.  The events of this world (that He has already seen) then become His foreknowledge.  This view attempts to affirm both God's soveriegn will to do what He pleases (as in Calvinism) and man's free will (as in Arminianism). (See Molonism)
4. Open Theism (His decrees or His wisdom) - Open Theism or Free-will Theism differs from the previous views because God does not have exhaustive or complete foreknowledge.  God does have complete knowledge of past and present events, but because the future does not yet exist, it is impossible for Him or anyone to know it.  God's foreknowledge then is either (1) the things He has decreed to do¹ or (2) things He is very certain, based on His knowledge of past and present human behavior and His wisdom, will most likely occur. (See Presentism)

Each of these view can find at least some scriptural support for their view of God's foreknowledge.  They each seek to explain foreknowledge based on or by defending certain attibutes of God.  Open Theism emphases God's love and relationship to creation as His primary trait.  Calvinism sees God's immuntability and unchangable nature as paramount to all of theology.  God cannot be changed in an manner, whether it be His nature or His choices.  Therefore every atom is controlled by God.

An Brief Analysis of These Views

God's foreknowledge must be in some way dynamic for it to be useful.  What this means is that if God's knowledge is based soley on future free actions of humans, He is powerless to change them.  He also cannot give advice to humans in prayer.  He can only tell them what He knows will happen in their life.  Therefore, strong Arminian foreknowledge must be rejected as untenable.  On the other hand, God can completely will every event in history (the Calvinist view) and every response to every prayer before creation.  Although the answers to prayer are determined in advance, the way we experience those answers can still be considered useful.

If instead of exhaustive control of every future, we find in scripture that man does have a free-will that affects the content of God's foreknowledge, then either Open Theism or Molism best explains this interaction.  In Open Theism, God knows everything there is to know, but because the future is unknowable (future free-will choices are unknowable), His foreknowledge is a function of His experiences with humans in the past and His wisdom to make educated guesses about the future (see Presentism).  This view allows God to be wrong about what might happen in the future.  Molonism views God's decision making and foreknowledge as happening before time. He is able to see every possible world He might create and how His every action and every human free-will choice will interact.  He then choose to create one of an infinite number of world's that conforms to His will.  This way God can will according to His good pleasure while still allowing man to have a free will that God can dynamically interact with.

Biblical Survey of Foreknowledge

Conclusions

It is this author's opinion that Molonism presents the best case for understanding God's foreknowledge and soveriegnty and man's free will.  Yet, the author realizes that Molonism is not a scriptural teaching and so should only be considered a valid explanation, and not an Biblical truth.