The Mystery of Holy Unction is one of the seven Mysteries (Sacraments), in which is accomplished the healing of soul and body through the prayerful calling down on the sick person the grace of God and anointing with Holy Oil. This Mystery was established by Jesus Christ (Mk 6:13). Of its existence in the ancient church witnesses the Catholic Epistle of the Apostle James: “Is any sick among you? Let them call for the elders of the church; and let them pray over him, anointing him with oil in the name of the Lord” (James 5:14). In the same Epistle, the forgiveness of sins is spoken of: “The prayer of faith shall save the sick, and the Lord shall raise him up; and if s/he has committed sins, they shall be forgiven him/her” (James 5:15).
The Holy Fathers write of the forgiveness of sins in the Mystery of Holy Unction: “The power of the Mystery of Unction is that in it are forgiven in particular those sins which were forgotten according to human weakness, and after forgiveness of sins it gives physical health, if it be God’s will” (St. Ambrose of Optina).