The ordination of priests - co-workers of the bishops
Through the sacrament of Holy Orders priests share in the universal dimensions of the mission that Christ entrusted to the apostles. The spiritual gift they have received in ordination prepares them, not for a limited and restricted mission, "but for the fullest, in fact the universal mission of salvation 'to the end of the earth,"' "prepared in spirit to preach the Gospel everywhere."
Source: Catechism of the Catholic Church (Vatican.va)