Sometimes it's good to take a familiar Bible passage and just think about it—come at it as if for the very first time, make a conscious effort to put aside for a while all the historical, cultural, and linguistic background one may have about the text, and simply listen quietly to what it has to say.
A while ago I decided to study in this way the account of Christ Jesus' temptation found in the fourth chapter of Matthew's Gospel. Although I wasn't expecting it, the most important insight I gained from my study served to challenge, head-on, the whole matter of self-doubt.
Self-doubt might not seem like such a terrible thing. It's better than conceit or arrogance, and there are times—for example, when an unfamiliar or demanding challenge arises—when it seems pretty sensible to question one's ability to complete an assignment successfully.