Reparation is a theological concept closely connected with those of atonement and satisfaction, and thus belonging to some of the deepest mysteries of the Christian Faith. It is the teaching of that Faith that man is a creature who has fallen from an original state of justice in which he was created, and that through the Incarnation, Passion, and Death of the Son of God he has been redeemed and restored again in a certain degree to the original condition. Although God might have condoned men's offenses gratuitously if He had chosen to do so, yet in His Providence He did not do this; He judged it better to demand satisfaction for the injuries which man had done Him. It is better for man's education that wrong doing on his part should entail the necessity of making satisfaction. This satisfaction was made adequately to God by the Sufferings, Passion, and Death of Jesus Christ, made Man for us. By voluntary submission to His Passion and Death on the Cross, Jesus Christ atoned for our disobedience and sin. He thus made reparation to the offended majesty of God for the outrages which the Creator so constantly suffers at the hands of His creatures. We are restored to grace through the merits of Christ's Death, and that grace enables us to add our prayers, labors, and trials to those of Our Lord "and fill up those things that are wanting of the sufferings of Christ" (Col., i, 24). We can thus make some sort of reparation to the justice of God for our own offenses against Him, and by virtue of the Communion of Saints, the oneness and solidarity of the mystical Body of Christ, we can also make satisfaction and reparation for the sins of others.
This theological doctrine, firmly rooted in the Christian Faith, is the foundation of the numerous confraternities and pious associations which have been founded, especially in modern times, to make reparation to God for the sins of men. Thus the Archconfraternity of Reparation for blasphemy and the neglect of Sunday was founded June 28, 1847, in the Church of St. Martin de La Noue at St. Dizier in France by Msgr. Parisis, Bishop of Langres. With a similar object, the Archconfraternity of the Holy Face was established at Tours, about 1851, through the piety of M. Dupont, the "holy man of Tours". In 1883 an association was formed in Rome to offer reparation to God on behalf of all nations. The idea of reparation is an essential element in the devotion of the Sacred Heart (see Devotion to the Heart of Jesus).
The Mass, the representation of the sacrifice of Calvary, is specially suited to make reparation for sin. One of the ends for which it is offered is the propitiation of God's wrath. A pious widow of Paris conceived the idea of promoting this object in 1862. By the authority of Pope Leo XIII the erection of the Archconfraternity of the Mass of Reparation was sanctioned in 1886.