The doubt referred to here is not the doubt of skeptics who poopoo anything that goes against or challenges their view or closely held beliefs as weird or untrue, but one who is challenged by their own questions and use doubt as a catalyst to action to discover truth for themselves.
This is especially important to the seeker of spiritual (or religious) truths and especially dealing with Jesus Christ, the Savior of all mankind. A foundation built upon a living, sustainable belief in the role of Jesus Christ has in the overall plan of this earth and the eternal lives of its inhabitants and how His atonement is (or can be) the greatest power for comfort, direction, inspiration and support to enduring all the trials of life for everyone, especially you, the reader.
Here is a worthy article to read on the subject: Doubt Doesn't Have to be Dangerous, by Terryl and Fiona Givens, which recently appeared on Meridian Magazine.
