As I visit a local bookshop here in Manila, I stumbled on one of Joyce Mayer (that popular Christian author and TV Evangelist) books. I think it's called "Battlefields of the Mind." It's a devotional book intended for the Christian audience, but what sparked my interests was that chapter on doubt and disbelief.
There are two things the author seems to imply in her book: That doubt and disbelief came from Satan, and according to her, "doubt (as Joyce Mayer described it) is an attack on beliefs, causing our thinking to waver between two opinions, while unbelief is a decision that leads to disobedience." Also, she continued, "... doubt is from the devil to discourage us from living our life’s purpose." The devil does not need to attack someone who doesn't believe. He attacks someone with faith and he uses doubt to chip away at it. Doubt is not from God. Unbelief, on the other hand, becomes disobedience because we are choosing not to believe the truths that God has put in our spirits. We are choosing not to utilize the faith that has been given to us. When God tells us something or asks us to do something, the faith to believe it or do it comes with the word from God.
It seems Ms. Mayer here is promoting blind obedience.