Heart of the Koran by Lex Hixon is one of the really great American metaphysics/theology works of the 20th Century. Still searching? Just read this book and give up absolutely.

"Waddya mean, give up? Are you nuts?" Okay, I can understand not giving up yet, you must be having too much fun. But this book is still worth the read due to its extraordinary initiatory and very loving description of Hixon’s trip to Paradise with the Prophet, peace to them, and to you too.