Open Theism, Jehovah's Witnesses, and the Omniscience of God

Part of what makes God what He is is His attributes of deity, just as what distinguishes a human from a cactus, for example, is the attributes of humanity. Those attributes of God are such things as eternality, omnipresence, and omniscience. Even the American most ignorant of true religion will have absorbed that definition, that God has always existed and always will exist, that He is everywhere, and that He knows everything.

But for the Christian, "common knowledge" is insufficient grounds for certainty, even in a culture with a biblical heritage, as in the United States. Plus, that common knowledge is being challenged by some in our day.

For example, both Jehovah's Witnesses and open theists deny His omniscience. They believe, correctly, that omniscience implies that events are not ultimately determined by the contingent decisions of men. And to admit that possibility would be to deny the hyper-Pelagianism of both groups.

To the Christian, the determiner of truth is the Word of God, the Bible, not common knowledge, because it alone is God's infallible testimony of truth. So, given that presupposition, does the Bible tell us that God knows all, past and present? Yes, it does.

O Lord, You have searched me and known me!
     You know when I sit down and when I rise up; 

You discern my thoughts from afar.   

     You search out my path and my lying down
and are acquainted with all my ways. 

     Even before a word is on my tongue,
behold, O Lord, You know it altogether. 

     You hem me in, behind and before,
and lay Your hand upon me. 

     Such knowledge is too wonderful for me;
it is high; I cannot attain it.

- Psalm 139:1-6 

David the Psalmist is in awe, because he is aware of God's exhaustive knowledge of his life, his surroundings, and even the thoughts of his mind. God is never ignorant of our thoughts or caught by surprise by our choices. 

"Known unto God are all his works from the beginning of the world" (Acts 15:18 KJV). This is an especially-important verse because it shuts down every claim of the Arminian. God does not act in response to the choices of men; He determined all things in prehistory. This also shuts the mouth of the Jehovah's Witness or open theist, because there is nothing unplanned to God, no suprises, no new information. He knows everything, and has known it since eternity past.