91 I therefore address myself to the recently baptized members of the young communities and young churches. Today, you are the hope of this two-thousand-year-old Church of ours: being young in faith, you must be like the first Christians and radiate enthusiasm and courage, in generous devotion to God and neighbor. In a word, you must set yourselves on the path of holiness. Only thus can you be a sign of God in the world and re-live in your own countries the missionary epic of the early Church. You will also be a leaven of missionary spirit for the older churches. For their part, missionaries should reflect on the duty of holiness required of them by the gift of their vocation, renew themselves in spirit day by day, and strive to update their doctrinal and pastoral formation. The missionary must be a "contemplative in action." He finds answers to problems in the light of God's word and in personal and community prayer. My contact with representatives of the non-Christian spiritual traditions, particularly those of Asia, has confirmed me in the view that the future of mission depends to a great extent on contemplation. Unless the missionary is a contemplative he cannot proclaim Christ in a credible way. He is a witness to the experience of God, and must be able to say with the apostles: "that which we have looked upon...concerning the word of life,...we proclaim also to you" (1 Jn 1:1-3). The missionary is a person of the Beatitudes. Before sending out the Twelve to evangelize, Jesus, in his "missionary discourse" (cf. Mt 10), teaches them the paths of mission: poverty, meekness, acceptance of suffering and persecution, the desire for justice and peace, charity - in other words, the Beatitudes, lived out in the apostolic life (cf. Mt 5:1-12). By living the Beatitudes, the missionary experiences and shows concretely that the kingdom of God has already come, and that he has accepted it. The characteristic of every authentic missionary life is the inner joy that comes from faith. In a world tormented and oppressed by so many problems, a world tempted to pessimism, the one who proclaims the "Good News" must be a person who has found true hope in Christ.
Source: Redemptoris Missio (Vatican.va)