This introduction provides context for the book "Heaven's Door" which is a continuation of "The Purification of the Soul". It discusses how the first book focused on inward purification while this one focuses on outward actions and their consequences. It emphasizes the importance of having a pure heart in order to guide others. It also highlights the need for detachment from worldly desires through knowledge of the afterlife and presence of Allah. The introduction concludes by mentioning heaven's eight gates and who they are for based on a saying from Ibn 'Abbas.