Raven...
I have read this quote many times on the internet as being attributed to Mr. Poe and, without exception, in the absence of any corrobrative tag to any recognized publication or his correspondence. In my forty five years of studying Poe, his life or any his works, I have never once come across a reproduction of this quote with the single exception of the internet.
There seems a common misconception that Poe was an atheist or harbored some deeply held distrust toward religion. This is simply not the case. Poe was raised in the Allan family by Frances Valentine Allan, his foster mother. Frances was a devoutly religious woman who attented church regularly and insisted that young Poe accompany her. If I recall correctly they attended Episcopalian services, though John Allan, Poe's foster father, was Presbyterian (I think)
At best, Poe was ambivalent toward religion itself but at times would invoke the name of God when it provided some desired effect he wished to convey.
I would suggest you visit the Edgar Allan Poe Society of Baltimore at
http://www.eapoe.org for some additional insight.
Regards,