A hard battle. . .
407 The doctrine of original sin, closely connected with that of redemption by Christ, provides lucid discernment of man's situation and activity in the world. By our first parents' sin, the devil has acquired a certain domination over man, even though man remains free. Original sin entails "captivity under the power of him who thenceforth had the power of death, that is, the devil".298 Ignorance of the fact that man has a wounded nature inclined to evil gives rise to serious errors in the areas of education, politics, social action299 and morals.
408 The consequences of original sin and of all men's personal sins put the world as a whole in the sinful condition aptly described in St. John's expression, "the sin of the world".300 This expression can also refer to the negative influence exerted on people by communal situations and social structures that are the fruit of men's sins.301
409 This dramatic situation of "the whole world [which] is in the power of the evil one"302 makes man's life a battle:
The whole of man's history has been the story of dour combat with the powers of evil, stretching, so our Lord tells us, from the very dawn of history until the last day. Finding himself in the midst of the battlefield man has to struggle to do what is right, and it is at great cost to himself, and aided by God's grace, that he succeeds in achieving his own inner integrity.303
IV. "YOU DID NOT ABANDON HIM TO THE POWER OF DEATH"
410 After his fall, man was not abandoned by God. On the contrary, God calls him and in a mysterious way heralds the coming victory over evil and his restoration from his fall.304 This passage in Genesis is called the Protoevangelium ("first gospel"): the first announcement of the Messiah and Redeemer, of a battle between the serpent and the Woman, and of the final victory of a descendant of hers.
411 The Christian tradition sees in this passage an announcement of the "New Adam" who, because he "became obedient unto death, even death on a cross", makes amends superabundantly for the disobedience, of Adam.305 Furthermore many Fathers and Doctors of the Church have seen the woman announced in the Protoevangelium as Mary, the mother of Christ, the "new Eve". Mary benefited first of all and uniquely from Christ's victory over sin: she was preserved from all stain of original sin and by a special grace of God committed no sin of any kind during her whole earthly life.306
412 But why did God not prevent the first man from sinning? St. Leo the Great responds, "Christ's inexpressible grace gave us blessings better than those the demon's envy had taken away."307 And St. Thomas Aquinas wrote, "There is nothing to prevent human nature's being raised up to something greater, even after sin; God permits evil in order to draw forth some greater good. Thus St. Paul says, 'Where sin increased, grace abounded all the more'; and the Exsultet sings, 'O happy fault,. . . which gained for us so great a Redeemer!'"308
413 "God did not make death, and he does not delight in the death of the living. . . It was through the devil's envy that death entered the world" (Wis 1:13; 2:24).
414 Satan or the devil and the other demons are fallen angels who have freely refused to serve God and his plan. Their choice against God is definitive. They try to associate man in their revolt against God.
415 "Although set by God in a state of rectitude man, enticed by the evil one, abused his freedom at the very start of history. He lifted himself up against God, and sought to attain his goal apart from him" (GS 13 § 1).
416 By his sin Adam, as the first man, lost the original holiness and justice he had received from God, not only for himself but for all human beings.
417 Adam and Eve transmitted to their descendants human nature wounded by their own first sin and hence deprived of original holiness and justice; this deprivation is called "original sin".
418 As a result of original sin, human nature is weakened in its powers, subject to ignorance, suffering and the domination of death, and inclined to sin (this inclination is called "concupiscence").
419 "We therefore hold, with the Council of Trent, that original sin is transmitted with human nature, "by propagation, not by imitation" and that it is. . . 'proper to each'" (Paul VI, CPG § 16).
420 The victory that Christ won over sin has given us greater blessings than those which sin had taken from us: "where sin increased, grace abounded all the more" (Rom 5:20).
421 Christians believe that "the world has been established and kept in being by the Creator's love; has fallen into slavery to sin but has been set free by Christ, crucified and risen to break the power of the evil one. . ." (GS 2 § 2).