I've dealt with the Mormons and the Roman Catholics for many years, and as a result it's easy for me to see how both organizations peddle the same demonic beliefs:

1. The Romanists are headed up by a Pope who speaks for God. The Mormons are headed up by a Prophet who speaks for God.;
2. The Romanists have literally added their version of Mary to the Godhead; the Mormons have literally added Joseph Smith to their polytheistic pantheon as the chief!
3. The Romanists pervert the Lord's Supper with their pagan transubstantiation doctrine; the Mormons profane the Lord's Supper with their Wonder Bread and Water.
4. The Romanists doll up their "priests" in multiple layers of "vestments." The Mormons wear bakers' hats, aprons, temple clothes, bridal veils, etc. in mystical rituals.
5. The Romanists exalt the messages of apparitions of Mary to the level of Gospel; the Mormon cult is based on the apparitions claimed by Joseph Smith.
6. The Romanists have a form of Church government which is a dictatorship; the Mormons have their Courts of Love before which a dissenter is hauled.
7. The Romanists used to murder by various methods those who opposed their heresies; Mormons had their apostate-killing Danites.
8. The Romanists have covered up the sexual perversions of their priests; the Mormons have covered up the sexual perversions of Joseph Smith.
9. The Romanists have "priests" who stand "in locos" (in the place of) Christ; the Mormons claim that their "god" acts through their "priesthood."
10. The Romanists have virtually added the "messages" of apparitions to their body of doctrine; the Mormons trust in "messages" called "revealtion," but are not.

And regarding these similarities, it appears to me that we are dealing with the same "spirit."