If God is unknowable in essence, how is God known at all? The Baha'i answer is the Manifestation of God: a being through whom the divine light is revealed to humanity. A Manifestation is neither God become flesh nor simply a wise human being, but a distinct rank of existence that reflects the attributes of God perfectly, as a clean mirror reflects the sun without the sun descending into it. Baha'u'llah describes the Manifestations as having two stations. In their essential station they are one, the same divine reality speaking in every age, so that Moses, Jesus, Muhammad and the rest can be said to be, in this sense, a single Speaker. In their distinctive station each is himself, with his own name, book and mission suited to his time. The founders of the world's religions are read as Manifestations, which grounds the Baha'i claim that those religions share one source.
Baha'i scholars, Moojan Momen among them, have compared the doctrine to the Islamic Sufi concept of the Perfect Man (al-insan al-kamil), developed especially by Ibn Arabi, and to the Hindu idea of avatar, while insisting on a real difference: a Manifestation is not God descending into matter, nor a returning soul, but a distinct and created rank of being that perfectly reflects, without embodying, the divine attributes, a distinction Baha'i apologetics have used to defend the teaching against charges of either pantheism or ordinary polytheistic incarnation from more traditional Islamic critics.