Here is a verse my church family looked at last night:

I am He that knoweth, and am Witness, saith Jehovah (Jeremiah 29:23)

Another pastor once wrote on this verse:

Fundamentally and simply, in all true policy, whether it be for the ordering of my family, or whether it be for the ordering of my city, or whether it be for the conduct of the national life, if this thing be true, that God knows, and witnesses, or makes known, then the first thing of importance is the acceptance of the fact.  That is fundamental, and apart from it there can be no application of this text whatever.

It may be that at this point some one will fall out, intellectually, and perhaps honestly.  I am not going to stay to argue, save to say one thing.  It may be some one will say, We cannot accept this position, we do not believe God knows; or if we believe God knows, we do not believe that He makes known, that He is in any sense revealing either Himself or other things to men.  Then I can only say to the man who takes up this position, anything else I may have to say will not affect him at all; he must drop out of my argument, and appeal; only I would remind him that the claim is so tremendous, that his solemn business is to settle once and for ever, as to whether it be true.  I can understand the man who cannot accept it immediately; I can understand the man who says, I am not sure of a God Who knows.  I can understand the man who says, Oh, I know there is a God Who knows in this way, but I am not sure that He reveals Himself.  I can understand the man who is facing that difficulty, and can sympathize with him, and believe in him.  But the one man that I cannot understand is the man who drifts for years, contented with that ignorance, and with no serious attempt to settle the question.  It is fundamental.  Either God is, or He is not.  Either God knows, or there is no infinite or final knowledge.  Either there is a God Who knows, or there is no final knowledge; for knowledge is partial in you and in me; and in this school and in that school; and in this philosophy and in that philosophy.  There is no final knowledge unless it is in God.  We must settle this, because if we are living in a world where there is no final and complete knowledge, things are different; we shall live differently, entirely.  That is the first thing to be settled.

A God Who knows is fundamental to Christianity.