From a Reddit Question and Answer with Greg Boyd:
What’s the most common misperception people have of open theism? How do you address that?
Boyd responds:
LOVE that you asked this! The most common misperception of the Open Theism, at least as I espouse it, is that it is about the scope of God’s knowledge rather than the nature of the future. Its reflected in the many critics who claim Open Theists “deny omniscience.” The truth is that we all affirm God is omniscient. The issues isn’t how much God knows, but what is the nature of the reality that God knows. And the only distinctive claim of Open Theists is that the reality God exhaustively knows INCLUDES POSSIBILITIES. Precisely because God is omniscient, who knows things exactly as they are. So he knows possibilities AS POSSIBILITIES, and actualities as actualities.
God is Open 
God knows everything that has happened, is happening, and will happen. He is not locked by time and space. He is in the future already and is in control of everything.
I dont think you are speaking about the God of the Bible. I will point you to this article by Roger Olson that points out the baselessness of timelessness:
http://www.patheos.com/blogs/rogereolson/2015/02/an-example-of-unwarranted-theological-speculation-divine-timelessness/
There are plenty of other resources on this site that show that interpretive Negative Theological concepts are not legitimately derived from the Bible.
Oh I assure you I am speaking of the God of the Bible. I don’t need to be pointed to an article, the Bible is clear that God knows everything. David clearly wrote about this in the Psalms.
I believe you are falling to take into account better and more probable understandings of the verses you are attempting to use for prooftexts. As an exercise in intellectual honesty, list out your prooftext and then list several reasonable understandings of those verses. Assuming concrete meaning into phrases negates everything we know about how Reading Comprehension works, as well as standard Jewish theology.
1 Sam. 16:7; 1 Chron. 28:9; Psa. 139:1-6; Jer. 17:10; Heb. 4:12-13
Seriously though, I asked a question for you to demonstrate your intellectual integrity on one of your prooftexts. Would you care to do that? We can take each prooftext in turn.
Sure. Psalm 139 God knows our words before we even utter them.
God is the beginning and the end.
Matthew 26, Jesus declares Peter’s denial. He already knew it would happen.
I could go on….
Yeah, your answer is ignoring the question. This is both a reading comprehension test and an intellectual honesty test. Again, the question:
As an exercise in intellectual honesty, list out your prooftext and then list several reasonable understandings of those verses.
How did I ignore the question? Perhaps you are ignoring my answer.
The question was not to say what you think the verse means. The question was to explore possible valid meanings.
I’ll give you an example. We will stick to Psalms 139:4
Psa 139:4 Even before a word is on my tongue, behold, O LORD, you know it altogether.
So, what is saying? What are some possibilities?
1. God knows all events past and future and thus has all the author’s words in mind.
2. God generally knows how people think and can determine what they will say, although they choose what to say
3. God knows people like we know computers and can look at our input-output to determine what will happen given certain inputs
4. God is so familiar and personal with the author (not necessarily everyone else on Earth) and thus knows what David will say. This has its own trope even:
http://tvtropes.org/pmwiki/pmwiki.php/Main/FinishingEachOthersSentences
5. God can read minds and the mind thinks the thoughts before they are said and thus God can intercept thoughts to know them before they are spoken. Almost like this video:
6. This sentence is figurative and idiomatic, meaning a concept similar to knowing words of people before they are spoken
7. This sentence is figurative and idiomatic representing something not familiar to modern readers
This is just a smattering of possibilities, and is not all-inclusive. The next job we have is to rack and stack answers based on the immediate context. Is there anything in the immediate context to bolster your favored interpretation? Is there anything in the immediate context that counters your favored interpretation? If we are going to refer to other Bible verses, we should default first to the ones that David had access to, and then move on to ones he did not. Those verses will also have to go through a similar rack-and-stack. Plus, we cannot just ignore counter-evidence.
Is this making sense to you? Proper theologians do not prooftext. They critically think.
Critically thinking doesn’t mean coming up with every off the wall interpretation possible. It means look at the plain reading of the text and how they would have understood that culturally.
You are building your own assumptions into the text. Then you are just discounting reasonable and possible alternative understandings. When you do this, you are showing that you lack critical thinking skills.
http://www.criticalthinking.org/pages/universal-intellectual-standards/527
Here is a follow up question, which one do I believe and why do I believe it?