398 In that sin man preferred himself to God and by that very act scorned him. He chose himself over and against God, against the requirements of his creaturely status and therefore against his own good. Created in a state of holiness, man was destined to be fully “divinized” by God in glory. Seduced by the devil, he wanted to “be like God”, but “without God, before God, and not in accordance with God”.
400 The harmony in which they had found themselves, thanks to original justice, is now destroyed: the control of the soul’s spiritual faculties over the body is shattered; the union of man and woman becomes subject to tensions, their relations henceforth marked by lust and domination. Harmony with creation is broken: visible creation has become alien and hostile to man. Because of man, creation is now subject “to its bondage to decay”. Finally, the consequence explicitly foretold for this disobedience will come true: man will “return to the ground”, for out of it he was taken. Death makes its entrance into human history.
405 Although it is proper to each individual, original sin does not have the character of a personal fault in any of Adam’s descendants. It is a deprivation of original holiness and justice, but human nature has not been totally corrupted: it is wounded in the natural powers proper to it, subject to ignorance, suffering and the dominion of death, and inclined to sin – an inclination to evil that is called concupiscence”. Baptism, by imparting the life of Christ’s grace, erases original sin and turns a man back towards God, but the consequences for nature, weakened and inclined to evil, persist in man and summon him to spiritual 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”. 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 action 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”. 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.
409 This dramatic situation of “the whole world [which] is in the power of the evil one” 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
All the above acts to outline the very reason for the ongoing battle. It has been waged since Adam. Satan – already in certain defeat due to the Resurrection of Christ – still wages it against individuals. Christ opened the gates of heaven to us and defeated Satan’s plan of causing all mankind to perish. But Satan can still wage battle against individuals. He does so through introduction of error in social structures, and countless other ways. Much of prophecy focuses on the different battles – physical and spiritual – which are all a derivative of this ongoing war waged by Satan against the saints.