No worries. I do not have all the answers and have to rely on my faith, it therefore perhaps is not surprising that I would struggle with my answers. If anyone feels my faith makes me cowardly then so be it, but of course I don't see it that way.
I don't think it makes you brave or cowardly, just wrong

A theist once said to an atheist "You won't change your mind and I won't change mine, so let's agree to disagree"
The atheist replied "You have that half right. You might not change your mind despite the evidence, but I on the other hand would change my mind if presented with evidence whether I liked what the evidence implied or not".
I am curious, what evidence would it take for you to change your mind and believe that Muhammad had nothing to do with God?