For those Christians that are continually plagued (or should I say blessed) with doubt, here is my prescription. Perform this prayer at least five times a day until you are cured.
"Dear God, grant me the full use of my intellectual faculties, especially the powers of logic and reason. Help me to seek truth through knowledge and not through myth. Provide me the wisdom to know the difference between what is real and what is imagined. Help me to have faith in Science which demands skepticism, scrutiny, testing and, above all, evidence. Lord, as the Bible says in 1 Corinthians 13:11, help me to give up my childish beliefs and start thinking like an adult. Amen."
You're welcome.