Over 700,000 copies of the original hardcover and paperback editions of this stunningly popular book have been sold. Karen Armstrong's superbly readable exploration of how the three dominant monotheistic religions of the world - Judaism, Christianity, and Islam - have shaped and altered the conception of God is a tour de force.

One of Britain's foremost commentators on religious affairs, Armstrong traces the history of how men and women have perceived and experienced God, from the time of Abraham to the present. From classical philosophy and medieval mysticism to the Reformation, the Enlightenment, and the modern age of skepticism, Armstrong performs the near miracle of distilling the intellectual history of monotheism into one compelling volume.

The Kitáb-i-Íqán: The Book of Certitude, authored by Bahá'u'lláh, is arguably one of the most important scriptural works in all of religious history. In this profound work, Bahá'u'lláh explains the underlying unity of the world's religions and describes the universality of the revelations humankind has received from the Prophets of God.

He illuminates their fundamental teachings and elucidates allegorical passages from the New Testament and the Qur'án that have given rise to misunderstandings among religious leaders, practitioners, and the public.

Written in the span of two days and two nights, The Book of Certitude is, in the words of its translator, Shoghi Effendi, the most important book written on the spiritual significance of the Bahá'í Faith.