I was just reading William Barclay - New Daily Study Bible Series. He was likening the 4 gospels to the vision of God. In Mark he's depicted as "the Man" (acquainted with our griefs) - in Matthew he's depicted as "the Lion" (Israel's expected Lion of the tribe of Judah) - in Luke he's depicted as "the Ox" (faithful and obedient) - in John he's depicted as "the Eagle" (showing us a heaven down view). I thought that was an interesting assessment.