The Doctrine and Covenants section 91 gives us God’s instruction about the “Apocrypha” but what is the Mormon Church’s view on The “new” scriptures that have come to light since. e.g. The Gospel of St. Thomas, The Book of Enoch, The Book of Jasher and others?
I feel that what you read in Doctrine and Covenants 91 about the Apocrypha would apply equally well to the books that you mention.
The “Gospel of St. Thomas” is a collection of teachings that some attribute to Jesus of Nazareth. Portions of Greek versions of the text were found at Oxyrhynchus, Egypt in the late 1800’s. A complete version in Coptic (an Egyptian language derived from the Greek alphabet) was found at Nag Hammadi, Egypt in 1945. The complete text has been dated to about 340 AD, while some of the Greek fragments have been dated as far back as 140 AD
The “Book of Enoch” was translated by Richard Laurence in 1821 from scrolls found hidden in caves in Ethiopia in 1773. These scrolls were evidently hidden in the same historical period as the Dead Sea Scrolls. The Richard Laurence translation should not be confused with “The Secrets of Enoch” written in 1925 by some new-age author.
There are several (as many as five) separate works entitled the Books of Jasher, all composed much later than Biblical times. One is a translation of a Hebrew book printed in 1613. Sepir Ha Yasher, the Hebrew title of this book, means the ‘Book of the Upright’, or ‘the Upright or Correct Record’.
There is also another spurious Book of Jasher, published 1750, in which Jasher is treated as the name of the author. This text covers much of the same ground as the traditional Mosaic books of the Bible, from the creation of the world to the death of Moses, albeit with several minor variations.
These books have not been canonized as scripture. Significantly, neither have the Dead Sea Scrolls, although books of scripture have been found among them. Further, any record relating to biblical content that was written many years after the events described would be highly suspect.
In addition, I feel certain that any record that the Mormon Church would accept as scripture would be revealed as such by specific revelation from God to His prophet representative on the earth—the President of The Church of Jesus Christ of Latter-day Saints.