Within the framework of this universal call, Christ, the High Priest, in his solicitude for the Church calls persons in every generation who are to care for his people. In particular, he calls to the ministerial priesthood men who are to exercise a fatherly role, the source of which is within the very fatherhood of God (cfr Eph 3,14). The mission of the priest in the Church is irreplaceable. Therefore, even if in some regions there is a scarcity of clergy, it should never be doubted that Christ continues to raise up men who, like the Apostles, leaving behind all other work, dedicate themselves completely to the celebration of the sacred mysteries, to the preaching of the Gospel and to pastoral ministry.
Pope Benedict XVI, Message for the 43rd World Day of Prayer for Vocations