"Strike the shepherd, and the sheep will be scattered."
In a vision, Zechariah hears God command that the shepherd be struck, resulting in a scattering of the sheep - two-thirds to destruction, and a third to testing and refining; hard times that will result in a renewed close relationship with God.
This prophecy is not merely acted out by Jesus (intentionally or unwittingly) or enacted against him (intentionally or unwittingly): Jesus, recorded by Matthew and Mark, actually quotes it, and interprets it to refer to his arrest and desertion by his diciples. They will scatter - but, when he has conquered death, they will be restored. One-by-one, following Peter in peer-pressure bravado, the disciples deny that they will desert Jesus. But Jesus is right in his understanding, and all but John run and hide. Peter is most vocal in his declaration of solidarity with Jesus; and therefore most visible in his denial that he knows Jesus...and singled-out once more in his restoration.
As John records, this restoration also ties-in with Zechariah's vision, in two ways:
the question of love, which tests like gold in the fire a renewed relationship between God, as represented by Jesus, and his people, as represented by Peter...
and the call to the scattered-and-brought-back sheep to become, in turn, a shepherd of the flock who one day will be stuck down...
And as such, this is a pattern that those who would follow Jesus may expect to see in their own lives - not an inevitability, but it should not surprise us if it is our experience. In times of extreme trial, we may scatter - but such failure is not the end. Jesus holds out the promise of restoration - and not merely forgiveness but a commissioning to greater responsibility; a call to follow him more closely, even to trials of our own...in which our serving may appear to have been in vain; but from which its greatest fruit is yet to be borne. The greater the trial, the greater the gain. For though, like Jesus himself, we are to pray that if there is any way that avoids trial God may take it, delivering us from evil may mean delivering through evil and out the other side victorious.