This diary was induced by the successful attempt to explain an Atheist's thoughts of Christmas as a religious holiday.
So discussing the deeper meanings of philosophical standpoints was besides the scope of that diary. I try to touch on these issues in this diary.
Firstly I need to define that these philosophical beliefs are not important without them being put to practice. Thus by definition nihilists ought to be suiciding at the moment of the realization of their beliefs.
In my view, monotheistic religions are a vague attempt of providing a reference point and protecting humans from the paralyzing realization resulting from the absurdity of the human condition.
Personally, I believe that things that all such things matter are make-believe. That's right, I believe that any faith not just in the supernatural but to friends, is make-believe. This system of faith only works because people buy into it. Faith matters because we, or our survival genes, compel ourselves - usually not by choice - to buy into it. While this convention disturbs me, I accept it and try move on. That is not nihilism. It's hypocrisy to the interest of self-preservation.
Similarly the more liberal versions of religions are general make-believe conventions that simply try to persuade humans to make the best of their lives so that they don't become paralyzed or self-destruct.
In this view of existence, everybody but acting nihilists, believe in the preservation of human life; people have simply devised different poetic forms of expressing these views and concluding that life is worth living.
The subcategorization of "believers" in humans vs god simply attempts to explain whether the origin and geographical existence (inside and by us or outside of and by God) of good and evil in different ways but has accepted the definition of good and evil. A further subcategorization of believers is based on how much of what we do comes from God or from us. This is the Palin/Falwell vs Obama/Kennedy version of religion.
These subcategorizations are important but not primary in answering the original question. As Camus wrote the primary philosophical debate is whether life is worth living. I wholly subscribe to this points of view. Nihilists don't.