at foundation.

The religion of God is the One Religion, and all the Prophets have taught
it, but it is a living and a growing thing, not lifeless and unchanging.
In the teaching of Moses we see the Bud; in that of Christ the Flower; in
that of Baha'u'llah the Fruit. The flower does not destroy the bud, nor
does the fruit destroy the flower. It destroys not, but fulfills. The bud
scales must fall in order that the flower may bloom, and the petals must
fall that the fruit may grow and ripen. Were the bud scales and the petals
wrong or useless, then, that they had to be discarded? Nay, both in their
time were right and necessary; without them there could have been no
fruit. So it is with the various prophetic teachings; their externals
change from age to age, but each revelation is the fulfillment of its
predecessors; they are not separate or incongruous, but different stages
in the life history of the One Religion, which has in turn been revealed
as seed, as bud and as flower, and now enters on the stage of fruition.

Infallibility of the Prophets

Baha'u'llah teaches that everyone endowed with the Station of Prophethood
is given sufficient proofs of His Mission, is entitled to claim obedience
from all men and has authority to abrogate, alter or add to the teachings
of His predecessors. In the Book of Iqan we read:--

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! Nay, the
manifold bounties of the Lord of all beings have, at all times,
through the Manifestations of His divine Essence, encompassed the
earth and all that dwell therein. ...

And yet, is not the object of every Revelation to effect a
transformation in the whole character of mankind, a transformation
that shall manifest itself both outwardly and inwardly, that shall
affect both its inner life and external conditions? For if the
character of mankind be not changed, the futility of God's
universal Manifestations would be apparent.--Kitab-i-Iqan, pp. 14,
240.

God is the One infallible Authority, and the Prophets are infallible
because Their Message is the Message of G