II. Vatican Council
Gaudium et spes
Chapter 1 The dignity of the human person
13. Although he was made by God in a state of holiness, from the very onset of his history man abused his liberty, at the urging of the Evil One. Man set himself against God and sought to attain his goal apart from God. Although they knew God, they did not glorify Him as God, but their senseless minds were darkened and they served the creature rather than the Creator.(3) What divine revelation makes known to us agrees with experience. Examining his heart, man finds that he has inclinations toward evil too, and is engulfed by manifold ills which cannot come from his good Creator. Often refusing to acknowledge God as his beginning, man has disrupted also his proper relationship to his own ultimate goal as well as his whole relationship toward himself and others and all created things.
Therefore man is split within himself. As a result, all of human life, whether individual or collective, shows itseLf to be a dramatic struggle between good and evil, between light and darkness. Indeed, man finds that by himself he is incapable of battling the assaults of evil successfully, so that everyone feels as though he is bound by chains. But the Lord Himself came to free and strengthen man, renewing him inwardly and casting out that "prince of this world" (John 12:31) who held him in the bondage of sin.(4) For sin has diminished man, blocking his path to fulfillment.
The call to grandeur and the depths of misery, both of which are a part of human experience, find their ultimate and simultaneous explanation in the light of this revelation.
3. Cf. Osee 2; Jer. 3:6-13; Ezech. 16 and 23; Is. 54.
4. Cf. Matt. 9: 15; Mark 2: 19-20; Luke 5:34-35; John 3:29; Cf. also 2 Cor. 11:2; Eph. 5:27; Apoc. 19:7-8; 21:2 and 9.
Chapter III Man's activity throughout the world
37. Sacred Scripture teaches the human family what the experience of the ages confirms: that while human progress is a great advantage to man, it brings with it a strong temptation. For when the order of values is jumbled and bad is mixed with the good, individuals and groups pay heed solely to their own interests, and not to those of others. Thus it happens that the world ceases to be a place of true brotherhood. In our own day, the magnified power of humanity threatens to destroy the race itself.
For a monumental struggle against the powers of darkness pervades the whole history of man. The battle was joined from the very origins of the world and will continue until the last day, as the Lord has attested.(8) Caught in this conflict, man is obliged to wrestle constantly if he is to cling to what is good, nor can he achieve his own integrity without great efforts and the help of God's grace.
That is why Christ's Church, trusting in the design of the Creator, acknowledges that human progress can serve man's true happiness, yet she cannot help echoing the Apostle's warning: "Be not conformed to this world" (Rom. 12:2). Here by the world is meant that spirit of vanity and malice which transforms into an instrument of sin those human energies intended for the service of God and man.
Hence if anyone wants to know how this unhappy situation can be overcome, Christians will tell him that all human activity, constantly imperiled by man's pride and deranged self-love, must be purified and perfected by the power of Christ's cross and resurrection. For redeemed by Christ and made a new creature in the Holy Spirit, man is able to love the things themselves created by God, and ought to do so. He can receive them from God and respect and reverence them as flowing constantly from the hand of God. Grateful to his Benefactor for these creatures, using and enjoying them in detachment and liberty of spirit, man is led forward into a true possession of them, as having nothing, yet possessing all things.(9) "All are yours, and you are Christ's, and Christ is God's" (1 Cor. 3:22-23).
8. Cf. Matt. 24:13; 13:24-30 and 36-43.
9. Cf. 2 Cor. 6:10.
6. Just as Christ was sent by the Father, so also He sent the apostles, filled with the Holy Spirit. This He did that, by preaching the gospel to every creature , they might proclaim that the Son of God, by His death and resurrection, had freed us from the power of Satan  and from death, and brought us into the kingdom of His Father. His purpose also was that they might accomplish the work of salvation which they had proclaimed, by means of sacrifice and sacraments, around which the entire liturgical life revolves.
 Cf. Mark 16:15.
 Cf. Acts 26:18.
By the proclamation of the Gospel she prepares her hearers to receive and profess the faith. She gives them the dispositions necessary for baptism, snatches them from the slavery of error and of idols and incorporates them in Christ so that through charity they may grow up into full maturity in Christ. Through her work, whatever good is in the minds and hearts of men, whatever good lies latent in the religious practices and cultures of diverse peoples, is not only saved from destruction but is also cleansed, raised up and perfected unto the glory of God, the confusion of the devil and the happiness of man. The obligation of spreading the faith is imposed on every disciple of Christ, according to his state.
35. Christ, the great Prophet, who proclaimed the Kingdom of His Father both by the testimony of His life and the power of His words, continually fulfills His prophetic office until the complete manifestation of glory. He does this not only through the hierarchy who teach in His name and with His authority, but also through the laity whom He made His witnesses and to whom He gave understanding of the faith (sensu fidei) and an attractiveness in speech(200) so that the power of the Gospel might shine forth in their daily social and family life. They conduct themselves as children of the promise, and thus strong in faith and in hope they make the most of the present,(201) and with patience await the glory that is to come.(202) Let them not, then, hide this hope in the depths of their hearts, but even in the program of their secular life let them express it by a continual conversion and by wrestling "against the world-rulers of this darkness, against the spiritual forces of wickedness(203).
200 Cf. Act. 2, 17-18; Apoc. 19, 10.
201 Cf. Eph. 5, 16; Col. 4, 5.
202 Cf. Rom. 8, 25.
203 Eph. 6, 12.fi3
3. This universal design of God for the salvation of the human race is carried out not only, as it were, secretly in the soul of a man, or by the attempts (even religious ones by which in diverse ways it seeks after God) if perchance it may contact Him or find Him, though He be not far from anyone of us (cf. Acts 17:27). For these attempts need to be enlightened and healed; even though, through the kindly workings of Divine Providence, they may sometimes serve as leading strings toward God, or as a preparation for the Gospel.(2) Now God, in order to establish peace or the communion of sinful human beings with Himself, as well as to fashion them into a fraternal community, did ordain to intervene in human history in a way both new and finally sending His Son, clothed in our flesh, in order that through Him He might snatch men from the power of darkness and Satan (cf. Col. 1:13; Acts 10:38) and reconcile the world to Himself in Him (cf. 2 Cor. 5:19). Him, then, by whom He made the world,(3) He appointed heir of all things, that in Him He might restore all (cf. Eph. 1:10).For Jesus Christ was sent into the world as a real mediator between God and men.