Grant I agree, to me, it is not black or white too! I am one of those non-religious spiritual types. Try to not be defined by a dogma or creed other than love, happiness, or compassion.
And being a warrior
Sadly I find the most anti-spiritual arguments ("thats just stupid") come from religious peoples. Like the fact that someone believing in something else somehow takes away from their chosen belief.
I see that a lot in martial arts. People jump at discrediting another martial art instead of just saying hey thats different good luck with that.
I'm not sure what the more learned aikido readers will think of this book but I personally found
Way of Aikido, The: Life Lessons from an American Sensei by George Leonard to be a very good read. One of my favorite books. (though take into consideration I'm new to all things aikido)
It's a basic look at Aikido and how you can apply the principals (I would say spirituality) to every day life, both for aikido students AND non aikido students.
I've read it twice and I've lent it to 3 other guys at work who enjoyed it (and decided to get their own copy to pass it on). Within the first 20 pages you'll read a very aikido way of dealing with verbal arguments.
Anyways, shameless plug there, that book might give you a good beginners look at the spiritual part of things without going too deep into it.