In the community of the faithful committed to his charge, the priest represents Christ. Thus, it is most fitting that in all things he should reproduce the image of Christ and in particular follow his example, both in his personal and in his apostolic life. To his children in Christ, the priest is a sign and a pledge of that sublime and new reality which is the kingdom of God; he dispenses it and he possesses it to a more perfect degree. Thus he nourishes the faith and hope of all Christians, who, as such, are bound to observe chastity according to their proper state of life. …

By reason of his celibacy the priest is a man alone: That is true, but his solitude is not meaningless emptiness because it is filled with God and the brimming riches of his kingdom. Moreover, he has prepared himself for this solitude — which should be an internal and external plenitude of charity — if he has chosen it with full understanding, and not through any proud desire to be different from the rest of men, or to withdraw himself from common responsibilities, or to alienate himself from his brothers, or to show contempt for the world. Though set apart from the world, the priest is not separated from the people of God, because he has been “appointed to act on behalf of men,” since he is consecrated completely to charity and to the work for which the Lord has chosen him.

Excerpted from Sacerdotalis Caelibatus, Pope Paul VI's 1967 encyclical on priestly celibacy.