Catechism of the Catholic Church

858 Jesus is the Father's Emissary. From the beginning of his ministry, he "called to him those whom he desired; .... And he appointed twelve, whom also he named apostles, to be with him, and to be sent out to preach." ³⁶⁸ From then on, they would also be his "emissaries" (Greek apostoloi). In them, Christ continues his own mission: "As the Father has sent me, even so I send you." ³⁶⁹ The apostles' ministry is the continuation of his mission; Jesus said to the Twelve: "he who receives you receives me." ³⁷⁰

859 Jesus unites them to the mission he received from the Father. As "the Son can do nothing of his own accord," but receives everything from the Father who sent him, so those whom Jesus sends can do nothing apart from him, ³⁷¹ from whom they received both the mandate for their mission and the power to carry it out. Christ's apostles knew that they were called by God as "ministers of a new covenant," "servants of God," "ambassadors for Christ," "servants of Christ and stewards of the mysteries of God." ³⁷²

860 In the office of the apostles there is one aspect that cannot be transmitted: to be the chosen witnesses of the Lord's Resurrection and so the foundation stones of the Church. But their office also has a permanent aspect. Christ promised to remain with them always. The divine mission entrusted by Jesus to them "will continue to the end of time, since the Gospel they handed on is the lasting source of all life for the Church. Therefore, . . . the apostles took care to appoint successors." ³⁷³