What does it mean to say the BoM has the "fulness" of the Gospel? Why doesn't the Book of Mormon include other teachings found in Church today, such as temple marriage, degrees of glory, etc.? According to the Book of Mormon, the "doctrine of Christ" are the foundational principles of the gospel of salvation, not meant to be confused with the higher ordinances of the temple, etc. The "Fulness" of the Gospel is the fulness of those principles. The Book of Mormon contains the pure and plain doctrine of Christ. It is augmented by the Bible, but also stands on its own as a witness for Christ's teachings.