A mortal sin (peccatum mortale), in Catholic theology, is a gravely sinful act which can lead to damnation if a person does not repent of the sin before death. It is alternatively called deadly, grave, and serious. A sin is considered to be "mortal" when its quality is such that it leads to a separation of that person from God's saving grace. Three conditions must together be met for a sin to be mortal: "Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent." The sin against the Holy Spirit and the sins that cry to Heaven for vengeance are considered especially serious. This type of sin is distinguished from a venial sin in that the latter simply leads to a weakening of a person's relationship with God. Despite its gravity, a person can repent of having committed a mortal sin. Such repentance is the primary requisite for forgiveness and absolution. Teaching on absolution from serious sins has varied somewhat throughout history. The current teaching for Catholics was formalized at the 16th-century Council of Trent. The term "mortal sin" is thought to be derived from the New Testament of the Bible. Specifically, it has been suggested by Jimmy Buehler from Theocast that the term comes from 1 John 5:16–17. In this particular verse, the author of the Epistle writes "There is a sin that leads to death." The concept is hinted at in some works of the early Fathers of the Church and explicit in others. In AD 385, Pacian of Barcelona, in his Sermon Exhorting to Penance, gives contempt of God, murder, and fornication as examples of "mortal" or "capital sins." In AD 393, St. Jerome writes: There are venial sins and there are mortal sins. It is one thing to owe ten thousand talents, another to owe but a farthing. We shall have to give an accounting for an idle word no less than for adultery. But to be made to blush and to be tortured are not the same thing; not the same thing to grow red in the face and to be in agony for a long time. . . .