One who puts on a mask and feigns himself to be what he is not. Our Lord severely rebuked the scribes and Pharisees for their hypocrisy. (Easton’s 1897 Bible Dictionary)
Mormons espouse the Book of Mormon in their writings, at church, and their missionaries proselytize with it. They however do not follow the teachings in the Book of Mormon as stated by Book of Mormon witness David Whitmer.
For example, the Holy Book of Mormon forbids the baptizing of children and yet they routinely baptize their children (for sins) at the age of eight. (D&C 68:27) Likewise they ignore the admonition by Jesus to not give communion to the unbaptized, i.e. not investigators or infants.
The most heinous of crimes being perpetuated by Mormons against the Book of Mormon is their doctrine of plural/celestial/eternal marriage, i.e. polygamy. Though not currently practiced, it is still a canonized doctrine (see D&C 132) and is being practiced in their temples.
Jesus warned against adding to the Holy Book of Mormon:
Whoso shall declare more or less than this (Book of Mormon) and establish it for my doctrine, the same cometh of evil…and the gates of hell stand open to receive such. (3 Nephi 11:40)
I will bring to light my gospel (Book of Mormon)…yea, the only doctrine which is in me. (D&C 10:62, dated Summer 1829)
Whoso among you shall do more or less than (Book of Mormon)…the gates of hell are ready open to receive them. (3 Nephi 18:13)
And every one that heareth these sayings of mine and doeth them not shall be likened unto a foolish man…and great was his fall! (3 Nephi 14:26-27)
We testify that when used together, the Bible and the Book of Mormon confound false doctrines. (Teachings of Ezra Taft Benson, p.63)
Until now, Mormons have not been alerted to the fact that they are being hypocritical when it comes to the Book of Mormon. If they choose against the Book of Mormon, the gates of hell stand open to receive them–according to Jesus.
If you received a witness by the Holy Spirit of the truthfulness of the Book of Mormon and choose now not to follow its precepts you will be committing blasphemy against the Holy Spirit and your fate will be sealed:
Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. (Matthew 12:31)