Christ is your shepherd and judge; he judges between his own sheep and other sheep. "My sheep," he says, "hear my voice and follow me." In this statement I find that all good shepherds are one in the one shepherd. It is not that good shepherds are lacking; they are there in the one shepherd. When we speak of “many” we refer to those who are divided from each other. Here only one is spoken of, because in this passage unity is commended. The reason why shepherds are not mentioned here but only one shepherd, is not because the Lord has failed to find anyone to whom to entrust his sheep; he entrusted the sheep to Peter because he had found Peter. Indeed, in the case of Peter he also commended the unity of the flock. There were many apostles, and yet to one only did he say: "Feed my sheep." Do not imagine that there will be no more good shepherds, or that we shall find them lacking, or that the Lord’s mercy will not produce and establish them.
Certainly, if there are good sheep there are also good shepherds; good sheep give rise to good shepherds. But all good shepherds are one in the one good shepherd; they form a unity. If only they feed the sheep, Christ is feeding the sheep. The friends of the bridegroom do not speak with their own voice, but they take great joy in listening to the bridegroom’s voice. Christ himself is the shepherd when they act as shepherds. “I feed them,” he says, because his voice is in their voice, his love in their love.
When he entrusted his sheep to Peter as one person to another, Christ chose to make Peter one with himself. He wanted to entrust him with the sheep in such a way that he himself might be the head and Peter might represent the body, that is, the Church. As bridegroom and bride, Christ and the Church were to be two in one flesh.
Accordingly, what does he say before he entrusts the sheep to Peter as to someone who is not separate from himself? "Peter, do you love me? He answered: I love you. And again: Do you love me? He answered: I love you. And a third time: Do you love me? He answered: I love you." He receives an assurance of love in order to establish unity. Christ is the one shepherd who is one with the other shepherds, and in whom they themselves are one.
Shepherds are not mentioned, but they are not passed over. Shepherds have cause for pride, but "if anyone boasts it should be in the Lord." This means that Christ should be the shepherd, that they should be shepherds for Christ, shepherds in Christ, not shepherds for themselves, apart from Christ. When the prophet said: "I will feed my sheep," it was not because of a lack of shepherds, as though he were foretelling those evil times to come and saying: “I have no one to whom I can entrust my sheep.” At a time when Peter himself, and the apostles too, were alive in the body, Christ, the one in whom alone all are one, said this: "I have other sheep that are not of this sheepfold; I must bring them in as well, so that there may be one flock and one shepherd."
All shepherds should therefore be one in the one good shepherd. All should speak with the one voice of the one shepherd, so that the sheep may hear and follow their shepherd; not this or that shepherd, but the one shepherd. All should speak with one voice in Christ, not with different voices. "Brethren, I beg all of you to say the same thing, and to have no dissensions among you." The sheep should hear this voice, a voice purified from all schism, freed from all heresy, and so follow their shepherd, who says: "My sheep hear my voice and follow me."
All good shepherds are one in the one shepherd
From a sermon On Pastors by Saint Augustine, bishop
The Liturgy of the Hours, Vol. IV, Office of Readings
Wednesday of the 25th Week in Ordinary Time