Why doesn't it fit?
I think it fits Christian theology 'cos Peter, the bumbling idiot,
has nothing but faith which he shows at the end, i.e. the upside
down crucification of Peter.
He obviously has no idea who Jesus was, how dare he rebuked Jesus
when the latter talked about the impending Passion event.
As chief apostle, he is a total disgrace among the 12, considering
how Paul rebuked him.