In his awesome book "New Seeds of Contemplation", Thomas Merton discusses the "theology of the devil". He describes many wrong attitudes, exaggerations, and errors that deceive many who think they are following Christ. What I found most interesting is the description of how "faith" is diabolically defined. This was written in 1961, before the popularity of the nonsense promoted by Oprah or the "word-faith" ideas of televangelists.
The theology of the devil is really not theology but magic. "Faith" in this theology is really not the acceptance of God Who reveals Himself as mercy. It is a psychological, subjective "force" which applies a kind of violence to reality in order to change it according to one's own whims. Faith is a kind of supereffective wishing: a mastery that comes from a special, mysteriously dynamic will power that is generated by "profound convictions". By virtue of this wonderful energy one can exert persuasive force even on God Himself and bend His will to one's own will. By this astounding new dynamic sould force of faith (which any quack can develop in you for an appropriate remuneration) you can turn God into a means to your own ends. We become civilized medicine men, and God becomes our servant. Though He is terrible in His own right, He respects our sorcery, He allows Himself to be tamed by it. He will appreciate our dynamis, and will reward it with success in everything we attempt. We will become popular because we have "faith". We will be rich because we have "faith". All our national enemies will come and lay down their arms at our feet because we have "faith". Business will boom all over the world, and we will be able to make money out of everything and everyone under the sun because of the charmed life we lead. We have faith.