The Announcement of the Gospel Today,. . . We hail the teaching of the Second Vatican Council, especially found in Lumen Gentium, Gaudium et Spes, and Ad Gentes, that refines the Church’s understanding of her evangelical duty, defining the entire Church as missionary, that all Christians, by reason of baptism, confirmation, and Eucharist, are evangelizers.
Between missio ad gentes and the New Evangelization
Yes, the Council reaffirmed, especially in Ad Gentes, there are explicit missionaries, sent to lands and peoples who have never heard the very Name by which all are saved, but also that no Christian is exempt from the duty of witnessing to Jesus and offering His invitation to others in his own day-to-day life.
Thus, mission became central to the life of every local church, to every believer. The context of mission shifted not only in a geographical sense, but in a theological sense, as mission applied not only to unbelievers but to believers, and some thoughtful people began to wonder if such a providential expansion of the concept of evangelization unintentionally diluted the emphasis of mission ad gentes.
Blessed John Paul II developed this fresh understanding, speaking of evangelizing cultures, since the engagement between faith and culture supplanted the relationship between church and state dominant prior to the Council, and included in this task the re-evangelizing of cultures that had once been the very engine of gospel values. The New Evangelization became the dare to apply the invitation of Jesus to conversion of heart not only ad extra but ad intra, to believers and cultures where the salt of the gospel had lost its tang. Thus, the missio is not only to New Guinea but to New York.
In Redemptoris Missio, #33, he elaborated upon this, noting primary evangelization -- the preaching of Jesus to lands and people unaware of His saving message -- the New Evangelization -- the rekindling of faith in persons and cultures where it has grown lackluster -- and the pastoral care of those daily living as believers.
We of course acknowledge that there can be no opposition between the missio ad gentes and the New Evangelization. It is not an “either-or” but a “both-and” proposition. The New Evangelization generates enthusiastic missionaries; those in the apostolate of the missio ad gentes require themselves to be constantly evangelized anew.
Even in the New Testament, to the very generation who had the missio ad gentes given by the Master at His ascension still ringing in their ears, Paul had to remind them to “stir into flame” the gift of faith given them, certainly an early instance of the New Evangelization. . . .
We as believers, must have at heart even those people who consider themselves agnostics or atheists. When we speak of a new evangelization these people are perhaps taken aback. They do not want to see themselves as an object of mission or to give up their freedom of thought and will. Yet the question of God remains present even for them. As the first step of evangelization we must seek to keep this quest alive; we must be concerned that human beings do not set aside the question of God, but rather see it as an essential question for their lives. We must make sure that they are open to this question and to the yearning concealed within. I think that today too the Church should open a sort of “Court of the Gentiles” in which people might in some way latch on to God, without knowing him and before gaining access to his mystery, at whose service the inner life of the Church stands. . . .
Here's a link to the full text at Vatican Radio.