Apostolic Exhortation on the Sacrament of Penance - Part 17 (Part II) - Pope John Paul II

Here of course it is a question of external radical manifestations: rejection of God, rejection of his grace and therefore opposition to the very source of salvation(89)-these are manifestations whereby a person seems to exclude himself voluntarily from the path of forgiveness. It is to be hoped that very few persist to the end in this attitude of rebellion or even defiance of God. Moreover, God in his merciful love is greater than our hearts, as St. John further teaches us,(90) and can overcome all our psychological and spiritual resistance. So that, as St. Thomas writes, "considering the omnipotence and mercy of God, no one should despair of the salvation of anyone in this life."(91)


But when we ponder the problem of a rebellious will meeting the infinitely just God, we cannot but experience feelings of salutary "fear and trembling," as St. Paul suggests.(92) Moreover, Jesus' warning about the sin "that will not be forgiven" confirms the existence of sins which can bring down on the sinner the punishment of "eternal death."


In the light of these and other passages of sacred Scripture, doctors and theologians, spiritual teachers and pastors have divided sins into mortal and venial. St. Augustine, among others, speaks of letalia or mortifera crimina, contrasting them with venialia, levia or quotidiana.(93) The meaning which he gives to these adjectives was to influence the successive magisterium of the church. After him, it was St. Thomas who was to formulate in the clearest possible terms the doctrine which became a constant in the church.


In defining and distinguishing between mortal and venial sins, St. Thomas and the theology of sin that has its source in him could not be unaware of the biblical reference and therefore of the concept of spiritual death. According to St. Thomas, in order to live spiritually man must remain in communion with the supreme principle of life, which is God, since God is the ultimate end of man' s being and acting. 

Now sin is a disorder perpetrated by the human being against this life-principle. And when through sin, the soul commits a disorder that reaches the point of turning away form its ultimate end God to which it is bound by charity, then the sin is mortal; on the other hand, whenever the disorder does not reach the point of a turning away from God, the sin is venial."(94) For this reason venial sin does not deprive the sinner of sanctifying grace, friendship with God, charity and therefore eternal happiness, whereas just such a deprivation is precisely the consequence of mortal sin.