Don't let Kitab ar-Ruh sit on your hard drive unread. Download it, print a chapter, and reflect. You will cry. You will fear. And ultimately, you will hope.
A primary source for free, public-domain Islamic texts. You can find various editions, including the popular abridged translation by Ismail Abdus Salaam. Kalamullah.com: Kitab Ar-ruh English Pdf