Atheism is the absence of reason..

[Kingpin]

Hello fellows... 

Bit catchy the title i know but i have a question.

I know that there are many much smarter and better ecudated people out there so i ask you (and I'm also in kind of a hurry   )
I am discussion with a believer and he just posted me this:

Atheism is the absence of reason..

HERE. you seem to be under the misconception that Atheism has anything thing to do with reality.

Atheism is a Lie. By definition and by logic.
Here. Let me break it down.

DEFINTIONs

FAITH = BELIEF WITHOUT EVIDENCE
KNOWING = BELIEF THROUGH EVIDENCE

BELIEF = ACCEPTANCE OF CLAIM with or without EVIDENCE (Correctness)
DISBELIEF = REJECTION OF CLAIM with or without EVIDENCE (incorrectness)

DO YOU AGREE TO THESE DEFINTIONS? THEY ARE VERY NEUTRAL.

CONSTRUCT 1
Premise 1: No one can define God. (True)
Premise 2: No one KNOWS if God exists or not..(True)
Conclusion: Any CLAIM to KNOW is a lie. (Valid and Sound)

CONSTRUCT 2
Premise 1: Believers HAVE FAITH God Exists. (True)
Premise 2: To HAVE FAITH is claim existence but without evidence (ie. not knowing.) (True)
Conclusion: Believers do not claim to KNOW God exists.(See conlcusion 1.). (VALID AND SOUND)

CONSTRUCT 3
Premise 1: Atheists disbelieve God Exists. (TRUE)
Premise 2: To disbelieve is to falsify a belief based on evidence. (ie. Knowing) (true)
Conclusion: Atheists claim to KNOW the Truth about God's existence. (see conclusion1. )
(Valid & Sound)

Premise 1: If any claim to know is a lie
Premise 2: And Atheists claim to know
Conclsuoin : Atheists lie.

Thats all. it APPLIES exactly the same to christians. That is the beauty of Logic. Impartiality.

Atheism is a lie. By utter logic. 
Now prove your atheism exists. 

Well i know his construct 3 is false. Wrong definition of disbelief, and definitely wrong conclusion since atheists dont claim to KNOW but...
Is this some kind of circular reasoning?

Any suggestions as how to reply are warmly welcome :
Cheers

Tiberius is correct in his deconstructing of the logical arguments.  As a theist and fellow fan of logic, I can only shake my head at his attempt.  I see where he was trying to go but as others pointed out he was defining atheism in broad terms.  What most atheists I have interacted with are really saying is something like this:

"You are making this claim for which I see no evidence for and have no personal experience with, so until you present some meaningful evidence that I can find persuasive I will operate on the assumption that your claim is false."

If I am mistaken in saying this, please feel free to correct me.

In my eyes, most atheists simply say, "I see no reason to believe a God exists"  They are not demonstrably saying "there is no God" because if they made such a statement they would then have to provide the evidence for that absolute statement.  

I think my best memory of debating with an atheist though was when he asked me if I thought God was material or immaterial.  I replied that I thought God was immaterial.  He then asked "can you tell me anything else that is absolute, immaterial and real?"  To which I responded, "the laws of logic".