Points to Reflect on Concerning Claims and Proofs
Maybe one point we can start from, is the notion that God in His mercy, would not send a Messenger to people without proofs, or without credentials and testimony. He would not expect people to obey any claimant that comes along, nor would He punish them for not following a Messenger, without first supplying them with the proofs they need:
"How far from the grace of the All-Bountiful and from His loving providence and tender mercies it is to single out a soul from amongst all men for the guidance of His creatures, and, on one hand, to withhold from Him the full measure of His divine testimony, and, on the other, inflict severe retribution on His people for having turned away from His chosen One!"
It should therefore be only natural for people to expect, or to look for proofs before they would consider any claim.
In fairness, we should examine (at least in part), the reasons which drew people in the past to accept and believe in the Prophets and Messengers we have come to know, and Whose authority we recognize. We should also remember that They were all initially rejected and denied, and therefore we should also examine the reasons for such rejection and denial, but that is a different (though related) issue.
On the one hand, we should be able to recognize that just as the sun stands in no need of proof other than itself, so it is that, when we get to know about the life and deeds of the Prophets and Messengers of God, we recognize that Their Proof lies also in Themselves. On the other hand, because of our preconceived ideas, we do need some proofs even before we allow ourselves to learn about Them . So what are some of the criteria we employed in accepting the Messengers of the past?
One of the traditional proofs, has been the Teachings, (Sayings or Writings) brought to us by the Founders of past religions. What we may call the "Book".
According to the Holy Qur'an, it is all the proof that's needed:
"Is it not enough for them that We have sent down unto Thee the Book?"
"We did send messengers before thee, and appointed for them wives and children: and it was never the part of a messenger to bring a sign except as Allah permitted (or commanded). For each period is a Book (revealed). Allah doth blot out or confirm what He pleaseth: with Him is the Mother of the Book. : Whether We shall show thee (within thy life-time) part of what we promised them or take to ourselves thy soul (before it is all accomplished),- thy duty is to make (the Message) reach them: it is our part to call them to account."
Although unlettered in the sciences of religion and theology, and with only the basics of education in calligraphy and sports required of the children of nobility in early nineteenth century Persia, Baha'u'llah left a legacy of tens of thousands of pages for the interested investigator to examine.
During the forty years of imprisonment and exile, Baha'u'llah, wrote over a hundred volumes in both Persian and Arabic, of what Baha'is consider to be divine revelation. Many of His Writings have been translated to over eight hundred different languages. Many of these are available in bookstores and over the Internet for the interested reader to examine.