The King describes his relationship with God in terms of the wilderness wandering (Ps. 78).  God is his Shepherd, who is leading on a journey into His holy presence.  But it isn’t until Jesus came that we found a sheep that was perfectly submissive to his Shepherd’s staff while living in this Fallen wilderness.  We sing this psalm as the flock that is following after the perfect Sheep, Jesus, journeying through this wilderness and yearning for our heavenly home (Ezek. 34).