Penal substitution is a theory of the atonement within Christian theology, especially associated with the Reformed tradition. It argues that Christ, by His sacrificial choice, was punished (penalised) in the place of sinners (substitution), thus satisfying the demands of justice so God can justly forgive the sins. It is a specific understanding of substitutionary atonement, where the substitutionary nature of Jesus' death is understood in the sense of a substitutionary punishment. Early church fathers who have expressed this notion of penal substitution are Justin Martyr (100-165), Eusebius of Caesarea (275-339), and Augustine of Hippo (354-430).
Instead of salvation being conditional upon sin, Roman Catholicism has long attached the belief in Jesus Christ to the concept of salvation itself, and for non-Christians has asserted various "dispensations" ranging from "eternal damnation" to "salvation conditional upon conversion." Catholic controversies regarding universalists, such as Origen, are notable events in Church history, and have typically resulted in the proclamation of Catholicism being the "one true faith," along with dispensationalist concepts.
Catholics profess belief that Jesus Christ brought about redemption from sin and assert that salvation is possible only within the Roman Catholic Church. This doctrine remains, but is not always articulated with clarity. Modern teaching usually uses language similar to the following: Jesus was a divine sacrifice who brought about "redemption for all mankind."
Roman Catholics believe "Man stands in need of salvation from God," and "Divine help comes to him in Christ through the law that guides him and the grace that sustains him." It was for our salvation that "God loved us and sent his Son to be the expiation for our sins; the Father has sent His Son as the Saviour of the world, and He was revealed to take away sins." "By His death (Jesus, the Son of God) has conquered death, and so opened the possibility of salvation to all men."
Roman Catholicism teaching on justification is the principal cause of division from Protestantism, and holds a soul is justified "by reason of a perfect act of charity elicited by a well disposed sinner or by virtue of the Sacrament either of Baptism or of Penance." This condition can be appropriated by proxy, in recognition of the faith of a qualified sponsor, and is held to be effected by an actual change in the recipient's heart, that of the infused love of God, so that the justified are not only reputed to be righteous, "but we are truly called and are just, receiving justice within us."
A further teaching is that this justification can be increased by doing works enabled by the grace of God dispensed through Roman Catholic sacraments, and which grace includes that of the merits of saints. Such works of faith are also held to help merit eternal life. Regarding those who co-operated with such grace, the Council of Trent concludes that "nothing further is wanting to the justified, to prevent their being accounted to have, by those very works which have been done in God, fully satisfied the divine law according to the state of this life, and to have truly merited eternal life." Canon 32 similarly states, "If anyone says that the good works of the one justified are in such manner the gifts of God that they are not also the good merits of him justified; or that the one justified by the good works that he performs by the grace of God and the merit of Jesus Christ, whose living member he is, does not truly merit an increase of grace, eternal life, and in case he dies in grace, the attainment of eternal life itself and also an increase of glory, let him be anathema."
Jesus Christ has provided the Church with "the fullness of the means of salvation which [the Father] has willed: correct and complete confession of faith, full sacramental life, and ordained ministry in apostolic succession." Baptism is necessary for salvation, and is sufficient for those who die as children and those permanently deprived of their use of reason. The sacrament of Penance is necessary for salvation for those who have fallen after Baptism, just as Baptism is necessary for salvation for those who have not yet been reborn. But these are not the only sacraments of importance for salvation: "The Church affirms that for believers the sacraments of the New Covenant are necessary for salvation." This holds especially for the Eucharist. "Every time this mystery is celebrated, the work of our redemption is carried on and we break the one bread that provides the medicine of immortality, the antidote for death, and the food that makes us live for ever in Jesus Christ."
At the same time, however, the Roman Catholic Church teaches that through the graces Jesus Christ won for humanity by sacrificing Himself on the cross, salvation is possible even for those outside the visible boundaries of the Church. Christians and even non-Christians, if in life they respond positively to the grace and truth that God reveals to them through the mercy of Christ may be saved. This may include awareness of an obligation to become part of the Catholic Church. In such cases, "they could not be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it, or to remain in it." Catholics believe that people, even those who are not explicitly Christian, have the moral law written in their hearts, according to Jeremiah 31: 33 (prophecy of new covenant): "I will write my law on their hearts." St Justin wrote that those who have not accepted Christ but follow the moral law of their hearts follow God, because it is God who has written the moral law in each person's heart. Though he may not explicitly recognise it, he has the spirit of Christ. St Thomas Aquinas, the premier theologian in the Catholic Church, explains this paradox as follows. If a person lives according to the natural law written on his heart, God will send him a means of knowing the truth by either natural or supernatural means; that is, he will send a missionary to teach him the faith or, if necessary, even an angel.
The Church expressly teaches that "it is necessary to hold for certain that they who labour in ignorance of the true religion, if this ignorance is invincible, will not be held guilty of this in the eyes of God," that "outside of the Church, nobody can hope for life or salvation unless he is excused through ignorance beyond his control," that "they who labour in invincible ignorance of our most holy religion and who, zealously keeping the natural law and its precepts engraved in the hearts of all by God, and being ready to obey God, live an honest and upright life, can, by the operating power of divine light and grace, attain eternal life.".