bidah

Bidah, from the Arabic bidʿa (بدعة), refers to religious novelty or innovation—an act, belief, or practice introduced into Islam after the time of Prophet Muhammad that has no basis in the Qur'an or Sunnah. Etymologically, bid’ah means "innovation" or "a new thing," derived from the root b-d-ʿ.

In many Islamic schools of jurisprudence, bid’ah denotes additions or alterations to prescribed worship that lack authentic evidence. Some scholars distinguish bid’ah sayyi’ah (blameworthy or harmful innovation) from bid’ah hasanah (rewardable or beneficial innovation), though the latter is contested and not universally accepted; many argue that any religious practice without a clear basis is prohibited.

The term emerged in early Islamic discourse as a moral warning against practices without prophetic precedent. Over time jurists and hadith scholars grappled with what constitutes valid ijtihad versus innovation, and debates continue about culturally embedded practices, such as celebrations of the Prophet’s birthday or other new ritual forms.

In Sunni and Shia contexts, assessments of bid’ah vary by tradition and authority. The concept is used to discourage ungrounded religious changes, while some modern scholars distinguish acceptable adaptations that align with core doctrines from harmful deviations. In practice, determinations often rely on evidence from the Qur’an, the Sunnah, and scholarly consensus, rather than cultural novelty alone.