Jesus speaks of himself as the Good Shepherd who gives eternal life to his sheep (cf. Jn 10: 28). This image of the shepherd is deeply rooted in the Old Testament and dear to Christian tradition. The Prophets attributed to David the title: "Shepherd of Israel", which hence possesses an indisputable messianic importance (cf. Ex 34: 23).
Jesus is the true Shepherd of Israel, since he is the Son of Man who desired to share the condition of human beings to give them new life and lead them to salvation.
Significantly, the Evangelist adds to the term "shepherd" the adjective kalós, good, which he only uses with reference to Jesus and his mission. In the account of the Wedding at Cana, the adjective kalós is also used twice to signify the wine offered by Jesus, and it is easy to see it as a symbol of the good wine of messianic times (cf. 2: 10).
"I give them (that is, to my sheep) eternal life and they shall never perish" (Jn 10: 28). These are the words of Jesus, who had said a little earlier, "the good shepherd lays down his life for his sheep" (cf. Jn 10: 11).
John uses the verb tithénai - to offer, which he repeats in the following verses (cf. 15, 17, 18). We find the same verb in the Last Supper narrative when Jesus "laid aside his garments" in order to "take" them back later (cf. Jn 13: 4, 12).
Thus, it is clear that the intention is to affirm that the Redeemer has absolute freedom to do with his life as he chooses and thereby give it up or take it back freely.
Christ is the true Good Shepherd who gave his life for his sheep, for us, sacrificing himself on the Cross. He knows his sheep and his sheep know him, just as the Father knows him and he knows the Father (cf. Jn 10: 14-15).
This is not a matter of mere intellectual knowledge but of a profound, personal relationship: a knowledge of the heart, of one who loves and one who is loved; of one who is faithful and one who knows how to be trustworthy.
It is a knowledge of love, by virtue of which the Pastor invites his sheep to follow him and which is fully manifest in the gift of eternal life that he offers to them (cf. Jn 10: 27-28).
[Pope Benedict, homily for priestly ordination 29 April 2007]
