May 15

Among the infidels are those who have repudiated His Self and risen up against His Cause, and who claim that these divine verses are contrived. Such also were the objections of the deniers of old, who now implore deliverance from the Fire.  Say:  Woe betide you for the idle words that proceed from your mouths!  If these verses be indeed contrived, then by what proof have ye believed in God? Produce it, if ye be men of understanding! Whensoever We revealed Our clear verses unto such men, they rejected them, and whensoever they beheld that which the combined forces of the earth are powerless to produce, they pronounced it sorcery. 
(Baha'u'llah, Suriy-i-Haykal, The Summons of the Lord of Hosts)