John’s gospel is known for its “I Am” sayings. Among the most familiar of all Jesus’ “I am” sayings is this one: “I am the good shepherd.” This comforting, caring image of the good, guardian shepherd is imprinted on the youngest children in Sunday school and carried forward into adulthood by the crozier, the shepherd’s crook, held by popes, cardinals and bishops.

Sheep and shepherds are everywhere in the Old Testament. Abraham, Moses, David—all took their turn at shepherding. It doesn’t seem surprising, then, that Jesus would appropriate the shepherd role for himself as well. Besides, Jesus was partial to common, ordinary metaphors. Where his hearers were used to thinking of growth in terms of the “mighty cedars of Lebanon,” Jesus lifted up grains of wheat and mustard seeds and “flowers …