Author: Blessed John Paul the Great | Source:
EWTN 
It is the same when we deal with death. It is often awaited even as a liberation from the suffering of this life. At the same time, it is not possible to ignore the fact that it constitutes as it were a definitive summing-up of the destructive work both in the bodily organism and in the psyche. But death primarily involves the dissolution of the entire psychophysical personality of man. The soul survives and subsists separated from the body, while the body is subjected to gradual decomposition according to the words of the Lord God, pronounced after the sin committed by man at the beginning of his earthly history: "You are dust and to dust you shall return." Therefore, even if death is not a form of suffering in the temporal sense of the word, even if in a certain way it is beyond all forms of suffering, at the same time the evil which the human being experiences in death has a definitive and total character. By His salvific work, the only-begotten Son liberates man from sin and death. First of all He blots out from human history the dominion of sin, which took root under the influence of the evil spirit beginning with original sin, and then He gives man the possibility of living in sanctifying grace. In the wake of His victory over sin, He also takes away the dominion of death, by His resurrection beginning the process of the future resurrection of the body. Both are essential conditions of "eternal life," that is, of man's definitive happiness in union with God; this means, for the saved, that in the eschatological perspective suffering is totally blotted out.
Prayers to Prepare for Death
Prayer for a Happy Death (Ven. John Henry Cardinal Newman)
O my Lord and Savior, support me in my last hour in the strong arms of Thy Sacraments and by the fresh fragrance of Thy consolations. Let the absolving words be said over me, and the holy oil sign and seal me; and let Thine own Body be my food, and Thy Blood my sprinkling; and let my sweet Mother, Mary, breathe on me, and my Angel whisper peace to me, and my glorious saints and my own dear patrons smile upon me, that, in them all and through them all, I may receive the gift of perseverence, and die as I desire to live, in Thy faith, in Thy Church, in Thy service, and in Thy love. Amen.
An Act of Resignation (Pope St. Pius X)
My Lord God, even now I accept at Thy hand, cheerfully and willingly, with all its anxieties, pains and sufferings, whatever kind of death it shall please Thee to be mine. Amen.
- Read also The Last Things at EWTN.