Part I-III. The Indispensability of the Ordained Ministery

For a community of the faithful to be called a Church, and indeed to truly be a Church, it cannot be guided according to political criteria or those of human organizations. Every particular Church owes its guidance to Christ since it was He who fundamentally linked apostolic mission to the Church and hence no community has the power to grant that mission to itself[40] or to delegate it. In effect, a canonical or juridical determination made by hierarchal authority is necessary for the exercise of the munus of teaching and governing.[41]

The ministerial priesthood is therefore necessary for a community to exist as "Church": "The ordained priesthood ought not to be thought of as existing [...] posterior to the ecclesial community, as if the Church could be imagined as already established without this priesthood".[42] Indeed, were a community to lack a priest, it would be deprived of the exercise and sacramental action of Christ, the Head and Pastor, which are essential for the very life of every ecclesial community.

Thus the ordained priesthood is absolutely irreplaceable. As an immediate consequence of this there is the necessity for a continuing, zealous and well-organized pastoral promotion of vocations so as to provide the Church with those ministers which she needs and to ensure a proper seminary training for those preparing for the Sacrament of Holy Orders. Any other solution to problems deriving from a shortage of sacred ministers can only lead to precarious consequences.

"The duty of fostering vocations falls on the whole Christian community, and they should discharge it principally by living full Christian lives".[43] By following Christ more closely and in overcoming indifference, all the faithful have a responsibility to foster a positive response to priestly vocation. This is especially true for those nations where a strong sense of materialism is evident.