In the ancient world oils were a basic medicine as ointments would be today, soothing, protecting and moistening wounds. They also became part of rituals in in many religions. The Hebrews used oil to anoint kings and prophets as signs of office and respect. The heads and feet of guests might be anointed with oils after the ritual washing on entering a house. We are Christians and “Christ” means the anointed one, so it would be amazing if the Church had never adopted any forms of anointing. If fact, the church uses oils in baptism, confirmation, and ordination and in what we now call the Anointing of the Sick.
In The Letter of James we hear of a practice in the very earliest days of the Church of praying over and anointing of the sick. The brief passage indicates this action relates to seeking redemption, healing and forgiveness of sins.
Is anyone among you suffering? He should pray. Is anyone in good spirits? He should sing praise. Is anyone among you sick? He should summon the presbyters of the church, and they should pray over him and anoint [him] with oil in the name of the Lord, and the prayer of faith will save the sick person, and the Lord will raise him up. If he has committed any sins, he will be forgiven.
As with most rituals the understanding and practice evolved over time. While the anointing was clearly not intended only for those in danger of death, that practice and understanding developed over time. We began to call the Sacrament Extreme Unction or in English the Last Rites. This is a powerful concept and persists in the minds of many fifty years after the Church reemphasized the broader meaning and use of the Sacrament and returned to a more ancient usage of titles.
While shifting away from empathizing the sacrament as one reserved for the danger of death, the Second Vatican Council stated
“Extreme unction,” which may also and more fittingly be called “anointing of the sick,” is not a sacrament for those only who are at the point of death. Hence, as soon as any one of the faithful begins to be in danger of death from sickness or old age, the fitting time for him to receive this sacrament has certainly already arrived. ( Constitution on the Sacred Liturgy #73).
Even those facing death in the near future receive a great benefit if they receive the sacrament while they are able to consciously enter into it. Many people are aware of some strain in their relation to God and his people. It would help relieve their stress and enter more positively into their passing into the next life, if they were afforded the opportunity while they can converse with the priest and understand the words of healing and forgiveness. When the individual is conscious, the anointing ritual also includes the possibility of reception of Reconciliation and Holy Communion.
The Catholic Catechism is a guide to the Church’s self-understanding as it has developed over the centuries under the guidance of the Holy Spirit, which we believe continues in the Church to this very day. From the Catholic Catechism found at http://www.usccb.org/catechism/text/
These are the summary articles on the Anointing of the Sick
1626 Is any among you sick? Let him call for the 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” (Jas 5:14-15).
1527 The sacrament of Anointing of the Sick has as its purpose the conferral of a special grace on the Christian experiencing the difficulties inherent in the condition of grave illness or old age.
1528 The proper time for receiving this holy anointing has certainly arrived when the believer begins to be in danger of death because of illness or old age.
1529 Each time a Christian falls seriously ill, he may receive the Anointing of the Sick, and also when, after he has received it, the illness worsens.
1530 Only priests (presbyters and bishops) can give the sacrament of the Anointing of the Sick, using oil blessed by the bishop, or if necessary by the celebrating presbyter himself.
1531 The celebration of the Anointing of the Sick consists essentially in the anointing of the forehead and hands of the sick person (in the Roman Rite) or of other parts of the body (in the Eastern rite), the anointing being accompanied by the liturgical prayer of the celebrant asking for the special grace of this sacrament.
1532 The special grace of the sacrament of the Anointing of the Sick has as its effects: —the uniting of the sick person to the passion of Christ, for his own good and that of the whole Church; — the strengthening, peace, and courage to endure in a Christian manner the sufferings of illness or old age; — the forgiveness of sins, if the sick person was not able to obtain it through the sacrament of Penance; — the restoration of health, if it is conducive to the salvation of his soul; — the preparation for passing over to eternal life.