Here is a common statement that is usually put to us as a question for us to prove.

"God would not call Joseph only to bring forth The Book of Mormon and nothing else. He restored the gospel; established the Kingdom, etc.."

We do have the prophecies regarding Joseph Smith from the The Book of Mormon and the Bible; and the words that the Lord spoke directly to him. It nowhere says Joseph was called to do anything more than to bring forth The Book of Mormon.

8. And I shall give unto him a commandment that he shall do none other work, save the work which I shall command him. (2 Nephi 3)

And you have a gift to translate the plates; and I have commanded that you should pretend to no other gift for I will grant unto you no other gift. (Book of Commandments IV:2)

Joseph had to change revelations to allow him to do more things. Here, Joseph added "coming forth of my church" to justify his church:

And to none else will I grant this power, to receive this same testimony among this generation, in this the beginning of the rising up and the coming forth of my church out of the wilderness — clear as the moon, and fair as the sun, and terrible as an army with banners.(D&C 5:14 compare with Book of Commandments IV:4.)

Joseph had to remove the word "reformation" which was a direct contradiction to a "restoration:"

And thus, if the people of this generation harden not their hearts, I will work a reformation among them. (D&C 5:20 compare with Book of Commandments IV:5.)

Joseph was only called to bring forth The Book of Mormon, which book was to finish the reforming that the great Reformers started 500 years ago.

Question: Mormons should ask themselves what would have happened to The Book of Mormon if Joseph had not sequestered it to his church?

Answer: Those many early Christian converts to The Book would have incoporated it into their own denomination.