There is a consistency with God quite lacking among idolators. And boy, are these "mormons" ever idolators! This has been known for millennia:
Psalm 83:1-2 Keep not thou silence, O God: hold not thy peace, and be not still, O God. For, lo, thine enemies make a tumult: and they that hate thee have lifted up the head.
The psalmist goes on to list several examples including:
.
. . • . Edom & the Ishmaelites
. . • . Moab & the Hagarenes
. . • . Gebal
. . • . Ammon
. . • . Amalek
. . • . Philistines & Tyrians
. . • . Assur
†
. . • . Midianites
. . • . Sisera
. . • . Jabin
. . • . Endor
. . • . Oreb
. . • . Zeeb
. . • . Zebah
. . • . Zalmunna
The Bible offers two pointers so we can decide who qualifies in the modern era. One explains how God responds to pagans and heretics helping us to identify such responses and the other is a reminder of how, once someone understands the reality of Christ, that message is not kept hidden but shines out like a candle giving light to the whole world. Continuing with the psalm:
Psalm 83:13-15 O my God, make them like a wheel; as the stubble before the wind. As the fire burneth a wood, and as the flame setteth the mountains on fire; so persecute them with thy tempest, and make them afraid with thy storm.
Of course God is responsible for storms and they speak to the majesty of His power. But there is a communication, ignored by everyone who makes idols, showing that although God controls the storm the storm is not God.
I Kings 19:11-12 And [God] said, Go forth, and stand upon the mount before the LORD. And, behold, the LORD passed by, and a great and strong wind rent the mountains, and brake in pieces the rocks before the LORD; but the LORD was not in the wind: and after the wind an earthquake; but the LORD was not in the earthquake: and after the earthquake a fire; but the LORD was not in the fire: and after the fire a still small voice.
Jesus
‡ is in charge of storms and calms them with a word - but preserves our freewill. Those ignoring His still small voice are living in darkness.
Mormons could be pagans or heathens or heretics, it's difficult to tell, but the idolatry is explicit and enough to tell us they're not Christians. How did they receive their message? Did it resemble a light shining forth or was it a hidden thing, let out bit by bit and never repeatable? Christ's light shines under its own steam. No seer stones required, no sitting behind a curtain muttering, no poking your head into a hat (and if someone hides the transcription, no replacement is possible) ultimately I suppose it's as dark inside a hat as it is under a bushel.
Mark 4:21 And [Jesus] said unto them, Is a candle brought to be put under a bushel, or under a bed? and not to be set on a candlestick?
† Assur had helped the children of Lot Genesis 19:36-38
‡ Mark 4:37-39