We don't know that much about Galileo's personal faith, but a persistent myth is that he had proven that the Earth revolves around the sun. Galileo himself knew very well that he did not have a very good case scientifically for this hypothesis. The geo-heliocentric model of Tycho Brahe, ignored by Galileo, had better scientific support at the time. This is hard to understand with a presentist view of history, where the past is understood in light of present knowledge. Upon investigating how scientists at the time reasoned, one finds instead that it is impossible to comprehend the Galileo affair without understanding the importance of Brahe's model.
