The Prophet (blessings and peace be upon him) said: «If anyone introduces into this affair of ours [Islam and the Sunnah] something that we have not commanded, that [innovation] is to be rejected.» (Reported by Bukhari and Muslim) Innovations into the religion, such as new rituals, new beliefs, or new methods of performing authentic rituals, are thus forbidden. The author discusses society's tendency to introduce innovations into religion, as proven by the fact that earlier divinely-revealed religions were corrupted by innovations. Then, the author describes the other evil consequences of bid'ah and explains how it can be prevented.