“Belief is not a simple mental procedure for anyone, and certainly not for the genuinely religious individual.
A certain righteous person used to say the opening words of Maimonides’ Thirteen Articles of Faith, “I believe with complete faith,” are not a declaration but a prayer, a prayer for the attainment of complete faith.
If the person can really shake off the mountains of dust of accumulated opinions and actions, and truly examine himself inwardly, he will find there the spark of faith that was never really extinguished.”
–Rabbi Adin Steinsaltz