Does the Bible Represent an Omniscient God?

I've previously posted as to why an omniscient God makes no sense, but theists continue to claim that the Lord is all-knowing. I assumed they came to this belief from the Bible, but now I'm not so sure.

Let's look at the story of Abraham and Isaac. Abe is commanded by God to sacrifice his son Isaac to prove his faith and obedience to the Lord. Abe moves ahead with the order preparing for the ritual killing and just before he lights his kid on fire, the Almighty says...

“Do not lay a hand on the boy. Do not do anything to him. Now I know that you fear God, because you have not withheld from me your son, your only son. ” 

Genesis 22 : 12 New International Version 

God knows now, meaning he didn't know then. If God knew then, why the charade of testing Abraham in the first place?

So where did the idea of omniscience come from, if not the Bible? Well...it still kinda came from the Bible. This is one of it's less publicized contradictions, even in the atheist community. The two passages that claim omniscience, according to About.com, are from Psalm and Isaiah. Let's check them out.

2 You know when I sit and when I rise; you perceive my thoughts from afar.
3 You discern my going out and my lying down; you are familiar with all my ways.
4 Before a word is on my tongue you, Lord, know it completely.
5 You hem me in behind and before, and you lay your hand upon me.
6 Such knowledge is too wonderful for me, too lofty for me to attain. 

Psalm 139:2-6 New International Version

I've read emo-school-girl poetry more interesting than this. This Psalm is clearly not the word of the Lord, it's a poem to the Lord. Surely the Genesis bit is more telling of God's superpowers, it is a direct quote, after all.

13 Who can fathom the Spirit of the Lord, or instruct the Lord as his counselor?
14 Whom did the Lord consult to enlighten him, and who taught him the right way? Who was it that taught him knowledge, or showed him the path of understanding? 

Isaiah 40:13-14 New International Version

Again, this is someone other than God talking about God. In fact, this guy's just asking questions. Rather good questions, actually. I'm guessing the answer is supposed to be "no one" meaning that God is omniscient, but I see these as skeptical questions that show another paradox of God's nature.

So there you have it, a couple believer's musings are the foundation for God's omniscience while the Lord acknowledges his own blind spot in regards to Abraham. How the hell is the Biblical take away an all-knowing deity? I don't get it.