I've always been fascinated by people who never doubt. They don't doubt that God exists, that someone is watching out for them, that people are basically good, that the government is working to make our lives better.... I am a doubter (not a cynic, however). I believe, but I have my doubts from time to time and sometimes they are pretty powerful. But I always come back to faith - faith in God and in human nature and (more rarely) in the good intentions of our politicians.
I always think that those who have no doubts are missing something in life. Doubt makes us search for truth and test premises and look for inconsistencies and attempt to reconcile facts. Living in doubt for an extended period of time can be depressing, however. Doubt ought to make us searchers and explorers until we find and discover. Then we become people of faith.
Use the power of your doubts to solidify your faith. Doubt freely and often. But end with solid belief.