'Yes the Claim has to be supported by the Message. The Message given by Allah is reflected from the Messenger. Their person and Their Life are the first example of the Message.
The Messenger is Born of the Holy Spirit, they are not men like us. So from birth, and even before birth, these potential Attributes can be seen and as Children they already show signs of what they will give to humanity.
Regards Tony
Salam
Quran reveals Mohammad's (s) authority. His Ahlulbayt (a) have his authority per Quran. Mohammad (s) is a Messenger to all humanity, and so they are authorities over all humanity as well. The final Authority from God is the Mahdi (a). Isa (a) will return with him and pray behind him.
I don't find Kitabal Aqdas any thing like Quran. Quran is much higher in eloquence, flow, sound (musical tone), and it has an Ahlulbayt who can perform miracles with it. God says he doesn't replace a sign except he brings the like of it or something better. And it has doors that open other doors. It's both manifest and inward, explicit and implicit, clear and subtle, but nothing of it is unclear.
I use to believe Taha and letters like that, we couldn't know the meaning easily. But even that becomes clear through itself and by miracle nature, you know which of the 14 mysterious letter sequences refer to which Ahlulbayt (a).
I honestly studied Bayani texts as well as Bahai texts since high school.
Not only do they not compare to Quran, they are no where near level to me as the words of Ahlulbayt (a) like Misbahal Shariah.
The way Imams (a) speak when you understand Quran, it's next level wisdom and eloquence as well. Of course, Quran is much higher then their words, but their words are also beyond fabrication.
That is not to say there are no false hadiths, but, they have words you can know are from them.
I honestly understand the concept you need humility to understand words of Ahlulbayt (a). You guys feel that is what is needed for Bahai scripture. I understand that.
But when I came to both, I find Quran and words of Ahlulbayt (a) much much higher.
I tell you what, if you can show me prayers that compare to Du'a Kumail or Sahifa Sajjadiya from your texts... then we can talk... but Quran is even much higher and subtle and amazing then words of Ahlulbayt (a).
I understand words of Quran and Ahlulbayt (A) words need humbleness. I try to be humble, give Bahai texts a chance. But from day of judgment explanations, to mess explanation of seal of Prophets in kitabal itqaan, I don't find it possible to be from God.
There is no comparison with Quran and Ahlulbayt (a) words. Nahjul balagha itself is higher in eloquence then your holy scriptures so let alone Quran.
Allah (swt) says if he replaces a sign, which Quran is a sign, and Quran and Ahlulbayt (a) are a sign together too since there is no way towards one without the other, that he replaces it with something like it (equal it brightness and sign and proof level) or better.
If a Prophet comes and does that, I will submit to him. I will accept we are wrong about seal of Prophets. But day of judgment and the sophistry games with it to be about Baha'allah, it makes Quran a messy book.
Even if there are to be more Prophets, Ba'ahallah can't be one to me.