Allah has created the mankind with for the purpose of worshiping Him. Proper worship depends mainly on the soundness of the Aqeedah of Tawheed, or the belief in the Oneness of Allah. Understanding the concept of Tawhid (Monotheism), on the other hand, helps the Muslim know Allah better.
This book defines the concept of Tauhid, and exposes dubious values and improper rituals that are conducive to Shirk, the gravest of all sins which denounces man to eternal suffering in Hell. It also discusses the status of the Prophet (S) and the incumbency of loving him. This book is a must for every Muslim.