Your faith is just that; faith. You believe in the word of God because, well, I'm not sure why. It speaks to you, perhaps. But faith is fallible. There are those who have faith in religions wholly at odds with Christianity. Is their faith wrong? What makes yours right?
The beliefs surrounding God has changed much over the centuries. It is not a constant. I don't find it particularly difficult to believe that a so-called heretical sect was wiped out of existence and left out of the record books. Remember, for a good long while only clerics were literate. If the Church wanted a story gone, who would preserve it?
And the submarine comment did not follow from anything I previously said. It was a strawman argument.
Now if you'll excuse me, I'm going to think unthinkable thoughts that will damn me for all Eternity.