Many years ago, in my high school chemistry class, a little poem was often quoted. Its effort at humor may have been lacking but the consequences of an erroneous belief were certainly well depicted. It goes
“Alas for little Willie,
We’ll ne’er see Willie more,
For what he thought was H2O,
Was H2 SO4.”
The statement "It doesn’t matter what you believe so long as you are sincere" is infinitely more dangerous in one’s spiritual life than in the physical world in which we live. Having a wrong belief in the physical world may lead to injury, sickness or death but in the spiritual world it ends in eternal death. The scripture concludes: "There is a way that seems right to a man, but its end is the way of death." Proverbs 14:12.