Many people do believe at least on some level; they know of Christ, and their hearts tell them: here is someone I can trust. Yet each of us also knows feelings of fear and anxiety, and these often lead to a suspicion and reserve. Something in us seeks Christ, and at the same time, something in us holds us back and makes us unwilling to open ourselves to him fully. But that is just what we must do. Openness is the first step to faith.
Source: Freedom from Sinful Thoughts