In the extended metaphor of the shepherd in John 10, Jesus keeps revising the dimensions and application of the metaphor as he drives home a variety of points, a few of which we may pick up.

(1) For the biblically literate, it would be difficult not to think of Ezekiel 34. There God denounces the false shepherds of Israel, and repeatedly says that a day is coming when he himself will be the shepherd of his people, feeding them, leading them, disciplining them. Jesus’s insistence that, so far as shepherds go, those who came before him “were thieves and robbers” (John 10:8), would call Ezekiel 34 to mind. Then, toward the end of that Old Testament chapter, God says he will place over his flock one shepherd — his servant David. Now the Good Shepherd is here, one with God (1:1), yet from David’s line.

(2) In defining himself as the “good shepherd,” Jesus says that the “good shepherd lays down his life for the sheep” (10:11). This pushes the metaphor to the wall. In real life, a good shepherd risks his life for his sheep, and may lose it. But he doesn’t voluntarily sacrifice his life for the sheep. For a start, who would look after the other sheep? And in any case, it would be inappropriate: risking your life to save the livestock is one thing, but actually choosing to die for them would be disproportionate. A human life is worth more than a flock of sheep.

(3) Yet in case we have not yet absorbed the incongruity of Jesus’s claim, he spells it out even more clearly. He is not simply risking his life. Not is he merely the pawn of vicious circumstances: no one can take his life from him. He is laying it down of his own accord (10:18). Indeed, the reason why his Father continues to love him is that the Son is perfectly obedient — and it is the Father’s good mandate that this Son lay down his life (10:17; cf. Phil. 2:6–8).

(4) Jesus’s sheep respond to his voice; others reject him. The implicit election is ubiquitous in the passage (e.g., 10:27–28).

(5) Jesus’s mission includes not only sheep among the Israelites, but other sheep that “are not of this sheep pen” (10:16). But if they are Jesus’s sheep, whether Jews or Gentiles, they “will listen to [his] voice, and there shall be one flock and one shepherd” (10:16). Here is the fulfillment of the promise that in Abraham’s offspring all the nations of the earth will be blessed. And this is also why, in the last analysis, there can never be more than one head of the church — Jesus Christ himself.