Baha'u'llah left an enormous body of writing, Baha'is speak of many volumes, which they regard as revealed scripture. Among the best known are the Kitab-i-Aqdas, the Most Holy Book, which sets out laws and the framework of Baha'i community life; the Kitab-i-Iqan, the Book of Certitude, an exposition of progressive revelation and the interpretation of prophecy; and the Hidden Words, a collection of short ethical and mystical utterances that functions almost as a devotional handbook.
A distinctive feature of the faith is its emphasis on an explicit Covenant governing succession and unity. Baha'u'llah appointed his eldest son, Abdu'l-Baha, as the authorized interpreter of his writings and the centre to whom the community should turn, a written provision intended to prevent the schisms that Baha'is see as having fractured earlier religions. Authority passed in turn to a Guardian and, since 1963, to an elected international body, the Universal House of Justice, seated with the faith's world centre at Haifa and Akka in present-day Israel.
The Baha'i Faith today is a small but genuinely worldwide religion, present in most countries, and its adherents continue to face severe persecution in the land of its origin, Iran, where they are the largest religious minority and are denied recognition.