The sun is its own proof, to all that have the power of perception.

When it rises we need no ancient predictions to assure us of its shining.

So with the Manifestation of God when He appears.

Were all the former prophecies swept into oblivion, He would still be His own abundant and sufficient proof to all whose spiritual sense are open.
Proofs of Prophethood Baha'u'llah asked no one to accept His statements and His tokens blindly.
On the contrary, He put in the very forefront of His teachings emphatic warnings against blind acceptance of authority, and urged all to open their eyes and ears, and use their own judgement, independently and fearlessly, in order to ascertain the truth.

He enjoined the fullest investigation and never concealed Himself, offering, as the supreme proofs of His Prophethood, His words and works and their effects in transforming the lives and characters of men.