The history of the second part of religion is unimportant, because it relates to the customs of this life only; but the foundation of the religion of God is one, and His Holiness Baha'u'llah has renewed that 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.