P1. If atheism is true, our sensory perception and cognitive faculties were not designed to fulfill a specific telos, namely, the acquisition of truth and discerning of reality as it actually is, but rather, evolved through processes which aimed solely at the passing on of the creature's DNA.
The user of the word "aimed" implies a specific telos. Rather if atheism is true nothing at all is designed to fulfill any specific telos. Rather we have features which promote the passing of creature's DNA because features which promote the passing of DNA are subsequently made more populous by said DNA by way of a positive feedback loop.
A minor quibble, but the point is essentially the same.
P2. The passing on of the creature's DNA does not necessarily entail truth.
What does this statement even mean?
P3. Therefore the atheist's sensory perceptions and cognitive faculties do not necessarily yield truth.
The fallibility of human sensory perceptions is pretty much a given in any worldview, even a Christian one.
P4. Therefore if atheism is true, there is no justification for believing anything to be true.
P4 does not follow from P3. Sensory perceptions and cognitive faculties do not necessarily yield truth but can possible yield truth. Now, whether justification for truth can be attained is something of an epistemological conundrum, but one that is not limited to atheism particularly.
P5. We intuit some things are in fact true, and do so with proper justification.
I would disagree that intuition alone provides sufficient justification for anything. I consider this premise as false.
P6. Therefore atheism is false.
P2 is nonsensical, P4 doesn't follow from P3, and P5 is false. Ergo the conclusion does not follow.