Regarding Ayn Rand, you wrote ... The problem is that she (materialists) can provide no coherent explanation for truth
With regard to religious "truth," Ayn Rand has a great deal to say about mysticism. Here is a short beginning, an excerpt from her essay "Faith and Force: The Destroyers of the Modern World."
Mysticism What is mysticism? Mysticism is the acceptance of allegations without evidence or proof, either apart from or against the evidence of one's senses and one's reason. Mysticism is the claim to some non-sensory, non-rational, non-definable, non-identifiable means of knowledge, such as "instinct," intuition," "revelation," or any form of "just knowing."
Reason is the perception of reality, and rests on a single axiom: the Law of Identity.
Mysticism is the claim to the perception of some other reality -- other than the one in which we live -- whose definition is only that it is not natural, it is supernatural, and is to be perceived by some form of unnatural or supernatural means.
But satisfying the rationalist, this start with self is true, for one person, "I AM" and Descartes makes his start with a presupposition that reflects being created in the image of I AM.
The personally, relationally perceived truth of this brings bring both responsibility and relief to us, meeting not only our rational minds but our hearts (sensibilities, feelings) and forming a wholly suitable position for our whole selves. Truth to us becomes fully truth. We find that thorough objectivity begins with subjectiveness to the ultimate subject and object, "I AM THAT I AM."
Suggest:
For Epistemelogical Distinctions:
http://www.freerepublic.com/focus/religion/834579/posts
For Political Distinctions:
http://www.freerepublic.com/focus/news/836099/posts