First some Introductory points: The Bab was a man who claimed he is the gate to Imam Mahdi (a.t.f.s), then claimed he is the Mahdi Himself, then he is a new Prophet and then he claimed he is God. This happened about 150 years ago in Persia. He appointed a man called Mirza Yahya Subh-i Azal as his successor and executor of his will. Mirza Yahya was the leader of the Babis until his half-brother Baha'u'llah (creator of the Baha'i cult) succeeded in sending him to the sidelines. Mirza Yahaya is greatly hated by Baha’is and regarded as one their greatest enemies. To put it in a nutshell, this is how he is viewed by Baha'is: “Mírzá Yaḥyá is scarcely spoken of, but when he is mentioned he is called Satan.” (E.G. Browne, Materials for the Study of the Babi Religion, p. 117)What most Baha’is don’t know or will not tell you is that according to the Bab, Mirza Yahya Subh-i Azal, was God. This is how the Bab’s will to Subh-i Azal starts: “Name of Azal, testify that there is no God but I, the dearest beloved. Then testify that there is no God but you, the victorious and permanent.”First the Bab states very explicitly that he is God (not a messenger from God or a manifestation of God, but God himself), then he tells Subh-i Azal that he too is God and should testify to this (seriously what the hell)! These statements being illogical and meaningless aside, according to the Bab Mirza Yahya Subh-i Azal is God and according to Baha’ullah he is the Satan and devil! Why should anyone takes the claims of Baha'u'llah seriously when he claims he is the one that the Bab had prophesied about when he doesn't have faith in the Bab's God and calls him Satan?And why should we take the Bab's claims seriously who claims he is God then Passes his Godhood to Mirza Yahya who is then deprived of his Godhood by Baha'u'llah and changed into satan?!Why do these people claim they are monotheists while the core of their beliefs is polytheism and belief in multiple human Gods (Baha'u'llah also claims he is God)?Where is the logic in any of these claims? Sources, scans and some other quotes here: http://www.bahaibahai.com/eng/index.php/articles?id=91