The Great Whore of Revelation 17 is the gross wickedness that is spread across the earth
Revelation 17:5
5 And upon her forehead was a name written, MYSTERY,
BABYLON THE GREAT, THE MOTHER OF HARLOTS AND ABOMINATIONS OF THE EARTH.
She is a direct opposite of the woman who is mentioned in Revelation 12.
Revelation 12:1
1 And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon under her feet, and upon her head a crown of twelve stars:
Doctrine and Covenants 133:5,7,14
5 Go ye out from Babylon. Be ye clean that bear the vessels of the Lord.
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7 Yea, verily I say unto you again, the time has come when the voice of the Lord is unto you: Go ye out of Babylon; gather ye out from among the nations, from the four winds, from one end of heaven to the other.
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14 Go ye out from among the nations, even from
Babylon, from the midst of wickedness, which is spiritual Babylon.