The Book of Abraham is part of the Pearl of Great Price, which mormons consider scripture. The papyri which Joseph Smith said he translated the Book of Abraham from have been exposed to be nothing more than funeral texts from ancient Egypt.
At least eight Egyptologists and semitists have studied the papyri and concluded that they were portions of ordinary funerary documents.
Egyptologist James H. Breasted of the University of Chicago said:
“[T]hese three facsimiles of Egyptian documents in the ‘Pearl of Great Price’ depict the most common objects in the Mortuary religion of Egypt. Joseph Smith’s interpretations of them as part of a unique revelation through Abraham, therefore, very clearly demonstrates that he was totally unacquainted with the significance of these documents and absolutely ignorant of the simplest facts of Egyptian writing and civilization.”
Flinders Petrie of London University even went so far as to say:
“It may be safely said that there is not one single word that is true in these explanations”.
Archibald Sayce, Oxford professor of Egyptology, wrote about the translations:
“It is difficult to deal seriously with Joseph Smith’s impudent fraud …. Smith has turned the goddess [Isis in Facsimile No. 3] into a king and Osiris into Abraham.”
Before the evidence mounted that exposed the papyri to be different than what Joseph Smith said they were, these drawings even appeared in some versions of LDS scriptures. The LDS church was quiet about these things for a long time, but has finally released an article on their official site recognizing that:
“Mormon and non-Mormon Egyptologists agree that the characters on the fragments do not match the translation given in the book of Abraham,”
though they give no good explanation as to why.
Most of the LDS apologetics want to say that that Joseph Smith just used the papyri as inspiration for the Book of Abraham, and that’s why it’s not a literal translation of the papyri, but Joseph Smith ruled that possibility out when he said he was:
“translating an alphabet to the Book of Abraham, and arranging a grammar of the Egyptian language as practiced by the ancients.”
Joseph Smith also said in his journal:
“This afternoon labored on the Egyptan alphabet, in company with brsr. O. Cowdery, and W.W.Phelps…”
With with Joseph Smith clearly attempting a literal translation, and after seeing that numerous Egyptologists agree that the Book of Abraham is not a translation of the papyri, it’s quite apparent his translation was completely bogus.
If the Pearl of Great Price was fraudulently translated, then what does that say for the Book of Mormon? If you combine this with the evidence of the Kinderhook plates being fake, one might cast serious doubt on Joseph Smith’s “translated” works, including the Book of Mormon.
More information on the Book of Abraham:
As a side note, please don’t confuse the Joseph Smith’s allegedly fraudulent Book of Abraham with the writings about Abraham in the Bible.