The test is not really to non-literal interpretations in general but
non-literal interpretations of early Genesis. I don't think anyone takes
literally Psalm 17:8 "Keep me as the apple of your eye; hide me in the shadow
of your wings."
To take this literally means that God is an apple-eyed bird! Thus the test is
to the specific portions of the Genesis which are said to be so linguistically
clearly to be taken non-literally.
glenn