The teacher who makes mistakes may need to be trained again, and he/she will eventually get it right. Good thing the world of Mathematicians always agree because the evidence proves their common understanding.
Believers in God, in the absence of any evidence, they need to always reassess their beliefs, but there's no certainty that they will ever get it right And the bad thing is that the world of religion always disagree, and not one believer can prove his belief.
Venus, your analogy couldn't be worse.
Belief in God is just as good and well supported as the belief in unicorns. No mockery intended, just reality