CIC 765 The Lord Jesus endowed his community with a structure that will remain until the Kingdom is fully achieved. Before all else there is the choice of the Twelve with Peter as their head.1 Representing the twelve tribes of Israel, they are the foundation stones of the new Jerusalem.2 The Twelve and the other disciples share in Christ’s mission and his power, but also in his lot.3 By all his actions, Christ prepares and builds his Church.

CIC 1506 Christ invites his disciples to follow him by taking up their cross in their turn. ..4 By following him they acquire a new outlook on illness and the sick. Jesus associates them with his own life of poverty and service. He makes them share in his ministry of compassion and healing: “So they went out and preached that men should repent. And they cast out many demons, and anointed with oil many that were sick and healed them.”.5

CIC 1511 The Church believes and confesses that among the seven sacraments there is one especially intended to strengthen those who are being tried by illness, the Anointing of the Sick:
This sacred anointing of the sick was instituted by Christ our Lord as a true and proper sacrament of the New Testament. It is alluded to indeed by Mark, but is recommended to the faithful and promulgated by James the apostle and brother of the Lord.6

CIC 1673 When the Church asks publicly and authoritatively in the name of Jesus Christ that a person or object be protected against the power of the Evil One and withdrawn from his dominion, it is called exorcism. Jesus performed exorcisms and from him the Church has received the power and office of exorcizing.7 In a simple form, exorcism is performed at the celebration of Baptism. The solemn exorcism, called “a major exorcism,” can be performed only by a priest and with the permission of the bishop. The priest must proceed with prudence, strictly observing the rules established by the Church. Exorcism is directed at the expulsion of demons or to the liberation from demonic possession through the spiritual authority which Jesus entrusted to his Church. Illness, especially psychological illness, is a very different matter; treating this is the concern of medical science. Therefore, before an exorcism is performed, it is important to ascertain that one is dealing with the presence of the Evil One, and not an illness.8

1 Cf. Mk 3:14-15.
2 Cf. Mt 19:28; Lk 22:30; Rev 21:12-14.
3 Cf. Mk 6:7; Lk 10:1-2; Mt 10:25; Jn 15:20.
4 Cf. Mt 10:38.
5 Mk 6:12-13.
6 Council Of Trent (1551): DS 1695; cf. Mk 6:13; Jas 5:14-15.
7 Cf. Mk 1:25-26; 3:15; 6:7, 13; 16:17.
8 Cf. CIC, can. 1172.