Illness can lead to anguish, self-absorption, sometimes even despair and revolt against God. It can also make a person more mature, helping him discern in his life what is not essential so that he can turn toward that which is. Very often illness provokes a search for God and a return to him. (CCC1500, 1501)
Jesus not only healed the sick, allowed Himself to be touched by the sick, but he also makes their misery His own. The Sacrament of Anointing of the Sick is attested to by St. James: "Is any among you sick? Let him call for the elders [presbyters] of the Church and let them pray over him, anointing him with oil in the name of the Lord; and the prayer of faith will save the sick man, and the Lord will raise him up; and if he has committed sins, he will be forgiven."
The sacrament of Anointing of the Sick is given to those who are seriously ill by anointing them on the forehead and hands with duly blessed oil - pressed from olives or from other plants - saying, only once: "Through this holy anointing may the Lord in his love and mercy help you with the grace of the Holy Spirit. May the Lord who frees you from sin save you and raise you up." (CCC 1513)
If a sick person who received this anointing recovers his health, he can in the case of another grave illness receive this sacrament again. If during the same illness the person's condition becomes more serious, the sacrament may be repeated. It is fitting to receive the Anointing of the Sick just prior to a serious operation. The same holds for the elderly whose frailty becomes more pronounced. (CCC1515)
Only priests (bishops and presbyters) are ministers of the Anointing of the Sick. It is the duty of pastors to instruct the faithful on the benefits of this sacrament. The faithful should encourage the sick to call for a priest to receive this sacrament. The sick should prepare themselves to receive it with good dispositions, assisted by their pastor and the whole ecclesial community, which is invited to surround the sick in a special way through their prayers and fraternal attention. (CCC1516)
The first grace of this sacrament is one of strengthening, peace and courage to overcome the difficulties that go with the condition of serious illness or the frailty of old age. This grace is a gift of the Holy Spirit, who renews trust and faith in God and strengthens against the temptations of the evil one, the temptation to discouragement and anguish in the face of death. This assistance from the Lord by the power of his Spirit is meant to lead the sick person to healing of the soul, but also of the body if such is God's will. Furthermore, "if he has committed sins, he will be forgiven". (1520)
By the grace of this sacrament the sick person receives the strength and the gift of uniting himself more closely to Christ's Passion: in a certain way he is consecrated to bear fruit by configuration to the Savior's redemptive Passion. Suffering, a consequence of original sin, acquires a new meaning; it becomes a participation in the saving work of Jesus.(CCC1521)
The Anointing of the Sick completes our conformity to the death and Resurrection of Christ, just as Baptism began it. (CCC 1523)