SCRIPTURAL SOURCE FOR THIS SACRAMENT: James 5:14-16; Colossians 1:24
The Church brings encouragement, strength, and the support of the Faith Community to the sick person. The one anointed is put into the Presence of the Suffering Christ. This Sacrament is for the sharing the Spirit of the Body with that "cell" in the Body that is sick, sharing the life-giving Spirit Who raised Jesus Christ's humanity from the dead and brought it into resurrected and everlasting life.
We bring to the person, who is now brushing with mortality and even death, the hope of the Resurrection along with its power to raise us up to a new and higher life.
In this action, with the laying-on of hands and the anointing with oil, we ordain the suffering person to participate in the sufferings of Christ. Why? For our redemption. The most powerful prayer of the Church is the redemptive suffering of Jesus Christ; the sick are ordained into it so that their sufferings can be converted into the prayer of the Suffering Servant, our Messiah (cf. Colossians 1:24).
Human suffering needs to be redeemed, to be transformed from a sign of sin and death into a sign of union with Christ and the way to higher human life freed from sin and death.
The Sacrament can bring with it the will, the choice, the decision to live. That's why doctors and hospitals like to have it around! Having received the Sacrament an individual might be motivated to live out more fully the life of God in Christ, a life dedicated to the overcoming of sin and suffering, replacing them with His holiness (wholeness) and peace.
Liberation from humiliation and a sense of being "useless" and a "burden" to loved ones.
The sacramental action can bring dignity to the sick person, replacing their humiliation with dignity, replacing their sense of being "useless" with a sense of purpose. The Faith Community comes to the bedside of the sick person to elicit a response, to give the ability to respond (hence, to give a response-ability to the person who is sick). The sick person becomes responsible to other "cells" in the Body of Christ, responsible to apply the merits of a faith-full and a hope-full suffering for their redemption and sanctification.
The anointed becomes "the person on the other side of the Cross" and is joined with Christ on the Cross in redemptive suffering for the sake of the Church. (Read Colossians 1:24-29. Perhaps that mysterious passage will not now be so mysterious!)
The past practice of the Church was to wait until the onset of death and then call the priest. This turned matters in to a foot-race with the Grim Reaper as the priest desperately dashed to the bedside of the dying person in the hope of arriving before Death did. This didn't exactly make the priest welcome as he entered the door!
There ought to be a community and/or family expression of ministering this Sacrament to the sick person. That ought to exist first, and then be capstoned by the celebration of this Sacrament.
Note again: Sacraments do things for us, not for God. Sacraments are events which express our faith position and in their celebration God's power is let loose in our lives. We don't perform a sacramental action and then sit back and expect God to do something for us. No, we respond to what God is already doing for us.
This is the last reception of Holy Communion for one who is already "on the way" (in via). Consequently, this is much more closely associated with the advent of death than is Anointing of the Sick, although the two can certainly be celebrated together!
Hopefully, Viaticum allows us to choose death. Sometimes the dying need to be given permission to let go and to die. "On the night before He died, a death He freely chose, Jesus took bread, said the blessing, broke the bread, and gave it...."
Holy Viaticum is the last solemn Communion joining the dying person to Christ as He moves once again through His Passover. It is a special sharing in Christ's Last Supper. It brings with it:
All of life is a rehearsal for death. Everyone dies! Our ability to die freely and peacefully depends upon our daily abilities to "die" to a compulsive possessiveness of God's creations. It is the Creator who is ultimately to be sought, not His creations!
We have to have lived a free life in the freedom of the sons and daughters of God in order to freely will and accept death. Death is purposeful if life has been purposeful. Death is liberation if life has been liberating. This requires a radical commitment to the reign of God (the Kingdom) and it brings with it a liberation from fear, confusion, and liberation from over-anxiety and darkness. It brings a self-identity that has meaning and purpose in living.
Theological Note: The purpose of all of the Sacraments is to allow us to assimilate the values, attitudes, commitments, mind, and heart (the Spirit) of Jesus Christ. This all becomes terribly meaningful and comes to a peak in this Sacrament given at the point of death. It therefore requires the support of the faith-full around us in order that we might sustain that self-direction, vision, and purpose. Dying people can have the clearest recognition of what is happening and what life is all about. It is their radical ordination into the Priesthood of Jesus Christ. We the living can receive the Presence of God's life from them!