I have several thoughts on this:
Firstly, your thread title sentence is grammatically incorrect. In the context of the sentence, “Atheist” should be in the plural form “Atheists”. If however it was your intention to refer to an individual named “Atheist” then “Do” should be rendered as ”Does”. May one respectfully suggest you exercise a tad more care when formulating sentences?
I would further suggest that your title relies on the unsupported assumption that atheists do, in fact Get Up In The Morning. Many may Get Up but many may not. We simply don’t know. A Citation would be appropriate here. Unsupported stereotyping is to be avoided.
Finally your excessive use of Capital Letters to prefix all words in the sentence is suggestive of an Obsessive Inclination. You might consider Talking To Someone About This.
I think that’s about it.
Ohh... why do I (an Atheist) get up in the morning? In my case I think the desperate urge to void ones bladder provides the necessary and reasonable motivation.
OB