As God at Christmas came to live among us and stay with us, one question crosses the two thousand year span of Christian history: “Why did he do it? Why did God become man?”
The chant the angels began singing in the grotto—“Glory to God in the highest and on earth peace to those on whom his favour rests” (Lk 2, 14)—can help answer this question. The canticle of the night before Christmas, which is now in the Gloria, belongs to the liturgy as do the other three canticles from the New Testament which refer to Jesus’ birth and infancy: the Benedictus, the Magnificat and the Nunc dimittis.
Whilst these are included respectively in the morning Lauds, the evening Vesper prayer, and the nightly Compline, the Gloria found its place in the Holy Mass. To the angels’ words a few acclamations were added: "We praise You. We bless You. We adore You. We glorify You. We give You thanks for Your great Glory.” Later “Lord God, Lamb of God, Son of the Father. You who take away the sins of the world, have mercy on us” were added to form an ariose hymn of praise that was sung the first time during Christmas mass and then in all feast days. Included at the beginning of the Eucharistic celebration, the Gloria underscores the existing continuity between and the birth and the death of Christ, between Christmas and Easter, which are indissoluble aspects of the one and the same mystery of salvation.
The Gospel says that the angelic multitude sang: “Glory to God in the highest, and on earth peace to people of good will”. The angels announced that the birth of Christ to the shepherds “is” glory to God in the Highest and peace to His people on earth. Therefore, these angelic words are conveniently placed on the grotto to explain the mystery of Christmas that is fulfilled in the nativity scene. The word “gloria” (doxa) indicates the splendour of God that his grateful creatures’ praise elicits. Paul said that it is “the knowledge of the glory of God on the face of (Jesus) Christ” (2 Cor 4, 6). “Peace" (eirene) summarise the fullness of the messianic gift, salvation, as the Apostle puts it, which is identified with Christ himself. “For he is our peace," (Eph 2, 14). There is, finally, a reference to men “of good will”. “Good will” (eudokia) would ordinarily make one think of men’s “good will”, but here it refers to God’s, boundless, “good will” towards men. Hence the Christmas message means that with the birth of Jesus, God has shown his good will towards all.
Let us get back to question “Why did God become man?” St Irenaeus said: “The word became the dispenser of the paternal grace for the benefit of men [. . .]. For the glory of God is a living man—vivens homo—; and the life of man consists in beholding God.” (Adv. Haer. IV, 20, 5.7).
God’s glory manifests itself in the salvation of man whom God loved so much, wrote John the Evangelist, “that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life,” (Jn 3, 16). Love is therefore the ultimate reason for Christ’s incarnation. Theologian H.U. von Balthasar’s reflection on the matter is eloquent. He wrote that “God is not, first of all, absolute power, but rather absolute love whose sovereignty does not manifest itself in keeping what is his, but in giving it up” (Mysterium paschale I, 4). The God that we see in the nativity scene is God-Love.
At this point the angels’ announcement sounds to us like an invitation: “Let there be” glory to God in the Highest, “let there be” peace to His people on earth”. The only way to glorify God and build peace on earth lies in humbly and trustingly welcome the gift of Christmas: love. The angels’ song can then become a prayer to repeat often, not only during the Christmas period. A hymn of praise to God in the highest and a fervent invocation of peace on earth that may turn into a concrete commitment to build it with our own life. This is the commitment Christmas gives us.