“Alif. Lám. Mím. No doubt is there about this Book: It is a guidance unto the God-fearing.”

"With unswerving vision, with pure heart, and sanctified spirit, consider attentively what God hath established as the testimony of guidance for His people in His Book, which is recognized as authentic by both the high and lowly. To this testimony we both, as well as all the peoples of the world, must cling, that through its light we may know and distinguish between truth and falsehood, guidance and error. Inasmuch as Muḥammad hath confined His testimonies to His Book and to His Family, and whereas the latter hath passed away, there remaineth His Book only as His one testimony amongst the people.

In the beginning of His Book He saith: “Alif. Lám. Mím. No doubt is there about this Book: It is a guidance unto the God-fearing.” 2 In the disconnected letters of the Qur’án the mysteries of the divine Essence are enshrined, and within their shells the pearls of His Unity are treasured. For lack of space We do not dwell upon them at this moment. Outwardly they signify Muḥammad Himself, Whom God addresseth saying: “O Muḥammad, there is no doubt nor uncertainty about this Book which hath been sent down from the heaven of divine Unity. In it is guidance unto them that fear God.” Consider, how He hath appointed and decreed this self-same Book, the Qur’án, as a guidance unto all that are in heaven and on earth. He, the divine Being, and unknowable Essence, hath, Himself, testified that this Book is, beyond all doubt and uncertainty, the guide of all mankind until the Day of Resurrection. And now, We ask, is it fair for this people to view with doubt and misgiving this most weighty Testimony, the divine origin of which God hath proclaimed, and pronounced it to be the embodiment of truth? Is it fair for them to turn away from the thing which He hath appointed as the supreme Instrument of guidance for attainment unto the loftiest summits of knowledge, and to seek aught else but that Book? How can they allow men’s absurd and foolish sayings to sow the seeds of distrust in their minds? How can they any longer idly contend that a certain person hath spoken this or that way, or that a certain thing did not come to pass? Had there been anything conceivable besides the Book of God which could prove a more potent instrument and a surer guide to mankind, would He have failed to reveal it in that verse?"

Bahá'u'lláh, The Kitáb-i-Íqán, pp.202-204

2. Qur’án 2:1