No vocation is born of itself or lives for itself. A vocation flows from the heart of God and blossoms in the good soil of faithful people, in the experience of fraternal love. Did not Jesus say: “By this all men will know that you are my disciples, if you have love for one another” (Jn 13:35) -Pope Francis, World Day of Prayer for Vocations, May 11, 2014

The Sacrament of Holy Orders is the continuation of Christ's priesthood, which He bestowed upon His Apostles; thus, the Catechism of the Catholic Church refers to the Sacrament of Holy Orders as "the Sacrament of Apostolic Ministry."

In the Sacrament of Holy Orders, a man is incorporated into the priesthood of Christ at one of three levels: the episcopate, the priesthood, or the diaconate.

The Sacrament of Holy Orders can be validly conferred only on baptized men, following the example set by Christ and His Apostles, who chose only men as their successors and collaborators. A man cannot demand ordination; the Church has the authority to determine eligibility for the Sacrament.