I think Coragyps was making a different point. You said that there would be nothing left of Christian or Jewish faith if we didn't accept the literal truth of creation, Noah's flood, the virgin birth, and so forth. Coragyps provided the example of his father who never accepted these things as literal and yet demonstrated his Christian faith through his 45 years as a missionary and minister. This is evidence that one doesn't have to accept a literal interpretation in order to have Christian faith.
--Percy