Endymion — Dan Simmons

It is 274 years after the Fall and the universe is in chaos. Raul Endymion, onetime shepherd and convicted murderer, is chosen as a pawn in a cosmic game whose outcome will determine the fate of humanity. Selected as a bodyguard to the next messiah, Endymion will cross time, space, and the very fabric of reality as her protector, lover, and finally disciple. At the same time, the enigmatic Shrike--part monster, part killing machine, part avenging angel--has also followed the girl into the 32nd century. Yet it is Endymion who has been chosen to rescue Aenea, against all odds. Now will her message change the universe--if she is willing to speak it... and if humankind is prepared to hear it?