And all flesh shall see the salvation of God” (Lk 3:6; Is 40:5). This, right from the start, sets the specific accent intended by Luke: the light of Jesus arises for all nations; it is essential for this salvation to be all-embracing and addressed to everyone, and it is thus present in the individual always with the accent on sharing, with the call to pass it on. You possess God only in community with others; you speak to God only if you call him “Our” Father, using the “we” that includes all of God’s children. Jesus is not the property of just one people or one organization. His domain is oecumenical, universal, as is conveyed in the account mentioning the emperor. Faith is the path offered to all peoples. The era of Jesus, the era of the Church, is the missionary era. Our faith is in touch with Jesus only if we understand and live it as missionaries, only if we truly desire that all flesh shall see the salvation of God. This word of promise and joy thus turns into a question for us, making visible the challenge and meaning of Advent. Only when all flesh beholds God is his coming complete; the new heavens and the new earth can come about only when available to all. This word constantly intends to open the heart of Christianity, indeed our own heart. Adveniat regnum tuum [thy Kingdom come]—this plea of Advent, put on our lips by the Lord himself, is prayed by us correctly only if we allow it to transform us; if we let it open us up to all of God’s children, all flesh shall see the salvation of God.
Ratzinger, J. (1992). Co-Workers of the Truth: Meditations for Every Day of the Year. (I. Grassl, Ed., M. F. McCarthy & L. Krauth, Trans.) (pp. 398–399). San Francisco: Ignatius Press.