Satan uses cunning illusions that undermine spirituality, said Elder Gene R. Cook of the Seventy at the April 1982 general conference.
"Satan, with an illusion, leads a man to puff himself up with pride to say, 'I am my own man. I know the Lord lives, but He expects me to handle this particular matter on my own and not bother Him with any details.' Not being familiar with the scriptures, the man may not know that Satan teaches the world there is no God. But to the Saints he simply says, 'There is a God, but He is only generally involved in your life. He would not specifically help you today.' Or he teaches the world not to pray, but to the Saints he simply says, 'Don't pray now. You don't feel like praying right now.' (See 2 Ne. 32:8.)
"Satan, in another illusion of vain imagination, teaches a man that the man is spiritual and humble. He begins to believe it and then acts in the eyes of the people as if he were. He begins to drift but full well believes, because of the illusion being created, that he is still on the strait and narrow. He develops a holier-than-thou attitude, but in his heart he is hardened, 'past feeling' (1 Ne. 17:45), and prideful. The master of illusion teaches men to honor the Lord with their lips, while their hearts are far from the Lord." (See Joseph Smith-History 1:19.)