For this reason, I remind you to stir into flame the gift of God that you have through the imposition of hands.
2 Timothy 1:6
For this reason I left you in Crete so that you might set right what remains to be done and appoint presbyters in
every town.
Titus 1:5
The whole church is a priestly people; through Baptism all the faithful share in the priesthood of Christ. The ministerial (sacramental) priesthood differs in essence from the common priesthood of the faithful because it confers a sacred power for the service of the faithful. The ordained ministers exercise their service for the People of God by teaching, divine worship, and pastoral governance. Since the beginning, Scripture witnesses the ordained ministry to be conferred and exercised in three degrees: that of bishops, that of presbyters, and that of deacons.
Catechism of the Catholic Church Numbers 1591-1593
The Sacrament of Holy Orders is conferred within Mass by the bishop through the laying on of hands followed by a solemn prayer of consecration asking God to grant the candidate for ordination the graces of the Holy Spirit required for his ministry. The Church confers the Sacrament of Orders on baptized men, whose suitability for the exercise of ordained ministry has been duly recognized. Church authority alone has the responsibility and right to call a man to receive the Holy Orders. In the Latin Church the Sacrament of Holy Orders for the presbyterate is normally conferred only on candidates who embrace celibacy freely and who publicly manifest their intention of staying celibate for the love of God’s kingdom and service of the people of God.
Catechism of the Catholic Church Numbers 1597-1600