Many people say "I don't believe," and may even be convinced of it in all sincerity.
But it is not at all so simple.
Heresy and atheism require that a person should at least know what he is rejecting.
When the modern Jew declares, "I don't believe," he is really saying that he does not believe in the things that religious people believe in.
Moreover, in most cases, what is really happening to the person is something altogether different.
Most concepts of belief and of Jewishness are acquired in the kindergarten years, with perhaps occasional additions in the preparation for bar mitzvah.
When these childish conceptions confront a man's adult knowledge, it is no wonder that they are promptly rejected as inappropriate in the declaration "I don't believe."
Often enough, someone who considers himself a wicked and even sinful person is only an innocent who does not even know enough to ask the right questions.
I don't mean to imply that when a person begins to ask the right questions he will immediately believe in Maimonides' Thirteen Articles of Faith.
Belief is not a simple mental procedure for anyone, and certainly not for the genuinely religious individual.
A certain tzadik (righteous person) used to say that the opening words of the Thirteen Articles of Faith, "I believe with complete faith," are not a declaration but a prayer, the prayer for the attainment of complete faith.
If a 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
From On Being Free, “Modern Man and His Prayer” p. 91 by Rabbi Adin Steinsaltz