Black by Ted Dekker
An incredible story of evil and rescue, betrayal and love, and a terrorist's threat unlike anything the human race has ever known. A virulent evil has been unleashed upon the people of earth. The only man who can stop it is Thomas Hunter, an unlikely hero whose life is stretched between two worlds. Every time he falls asleep in one reality, he awakens in the other. Soon Thomas no longer knows which reality is real. Yet it quickly becomes apparent that his choices in each world impact the other-and that the fate of both rests in his hands.
(This synopsis hardly does the story justice, in my opinion.)
Ted Dekker wrote 3 books in the original Circle series. He has written two other complete series (3 and 4 book sets) whose stories and characters intertwine and follow the same theme throughout-good vs. evil and man's free will to choose.
Black is the first book in the Circle series followed by Red and White (the most amazing stories I've ever read). I am reading the part when Thomas, who up until now is a man of little faith, encounters Elyon (God) for the first time.
(I apologize for the slight buzz... and the part where I bang my leg into the desk trying to reposition myself in my chair.) :o)