Atheism is the absence of reason..

[Vault Boy]

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