The Kitáb-i-Íqán, or the Book of Certitude, is the primary doctrinal work of the Bahá’í Faith, written by Bahá'u'lláh in 1861. The Guardian (Shoghi Effendi) explained that it is "the most important book written on the spiritual significance of the Bahá’í Faith". It was written in response to the questions of the Báb’s maternal uncle and systematically argues the case for an allegorical and broader interpretation of the scriptures. It argues the utter impossibility of approaching truth while the heart is the slightest biased by prejudice. Although addressing spiritual truth, the implication for foundation of all truth, for science itself, is clear. The book was included in a short list of books which every Baha'i should master before attempting to teach others. The Guardian warned, in reference to this book, that "a great harm is done by starting to teach without being thoroughly grounded in the literature."
The core purpose of the Kitáb-i-Íqán is to provide a hermeneutical key to scripture interpretation, advocating for an allegorical understanding and emphasizing the need to approach spiritual truths without prejudice.
It's viewed as fundamental because it outlines the principles of scriptural interpretation foundational to Bahá’í belief and prepares believers for a profound understanding of their faith's spiritual dimensions.
The book vehemently argues that the pursuit of truth is hindered by even the slightest prejudice, advocating for an unbiased, open-hearted approach to spiritual inquiry and understanding.
Bahá'u'lláh wrote the Kitáb-i-Íqán in response to questions posed by the Báb's uncle, offering a comprehensive treatment of the themes he inquired about, themed around certitude in faith.
It discusses the cyclical nature of religious revelation, the roles of various Prophets, and the continuity of divine guidance, highlighting the concept of 'progressive revelation'.
Through its allegorical interpretations of religious texts and the concept of unity in all religions, it offers a framework for appreciating the underlying oneness and fosters interfaith dialogue.
Mastering its teachings ensures a well-grounded understanding of the faith's core principles, equipping believers to share Bahá’í concepts accurately and effectively.
The Kitáb-i-Íqán implicitly suggests that the unbiased search for truth is essential in both science and religion, uniting them in their quest for understanding reality.