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. 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, 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. Since He is God, all divine fullness dwells bodily in Him (Gal. 2:9). According to His human nature, on the other hand, He is the new Adam, made head of a renewed humanity, and full of grace and of truth (John 1:14). Therefore the Son of God walked the ways of a true Incarnation that He might make men sharers in the nature of God: made poor for our sakes, though He had been rich, in order that His poverty might enrich us (2 Cor. 8:9). The Son of Man came not that He might be served, but that He might be a servant, and give His life as a ransom for the many - that is, for all (cf. Mark 10:45). The Fathers of the Church proclaim without hesitation that what has not been taken up by Christ is not made whole. Now, what He took up was our entire human nature such as it is found among us poor wretches, save only sin (cf. Heb. 4:15; 9.28). For Christ said concerning Himself, He whom the Father sanctified and sent into the world (cf. John 10:36): the Spirit of the Lord is upon me, because He anointed me; to bring good news to the poor He sent me, to heal the broken - hearted, to proclaim to the captives release, and sight to the blind" (Luke 4:18). And again: "The Son of Man has come to seek and to save what was lost" (Luke 19:10). But what the Lord preached that one time, or what was wrought in Him for the saving of the human race, must be spread abroad and published to the ends of the earth (Acts 1:8), beginning from Jerusalem (cf. Luke 24:27), so that what He accomplished at that one time for the salvation of all, may in the course of time come to achieve its effect in all.
Source: Ad Gentes (Vatican.va)