This is the Gregorian introit of the Second Sunday of Advent:
“People (of) Sion, behold the Lord will come to save the nations. And the Lord will make heard the glory of his voice in the joy of your heart. You who reigns over Israel, give ear, who leads Joseph like a sheep.” (The text is compiled of verses from Is 30 and Ps 80.)
Among the four introits of the Advent Sundays – Ad te levavi animam meam, Gaudete in Domino semper, and Rorate caeli desuper being the other three – this might be the least famous one. But it is a very beautiful piece that says much about the theology of Advent.
As an altar boy, I was taught that Advent reminds us of the times when Jesus had not yet been born. Christians reenact what it was like to wait for the Redeemer, and after a symbolic season of four Sundays, the Redeemer appears on Christmas. There is some truth in this interpretation, but not very much. Advent is not a simulation of anything – just as Good Friday is not a day of sorrow for a dead friend, but a day of adoration of the one who did not refuse the Cross.
Advent is not a “What-if?” or “What-was-it-like?” season. Advent expresses human existence in the course of time and interprets this existence as full of insecurity, but also full of hope. This hope is not under our control and not yet fulfilled, but nevertheless is indestructible. The introit Populus Sion reaches its highest notes at the words faciet (“Yes, he will for sure!”) and gloriam vocis suae (“He is raising his voice!”) and then again in the standardized melody of the verse Qui regis Israel which is not a proposition but an appeal.
The entire chant is sung eschatology. It expresses the tension between “already” and “not yet” which shapes human existence on its way to the unknown future, but at the same time it makes audible the hope that is at the core of Christianity. Thus, Advent is not about what it was like to live before Jesus. It is about what life is like here and now – and how Christians should deal with the tension between “already” and “not yet.”
Furthermore, there is the beautiful ending of the antiphon: Where can the voice of God’s glory be heard? In laetitia cordis vestri – in the joy of your heart. The melody protracts the final syllable of laetitia although that syllable is not naturally stressed (and the medieval neumes even intensify that effect). Tension is raised here, something very important is about to come: what laetitia, what joy? – The joy in our hearts! The biblical God is no stranger to us. The relationship to him is intimate and natural. In the course of time, this relationship might be as fragile as happiness, but it is also as real as happiness.
Advent is the Christian interpretation of the human existence moving towards the future. Being a human is very exciting, and Advent offers an opportunity to deepen that experience. Advent does not hide all insecurity and fragility, but it impregnates all pleas and open questions with hope and confidence, and it sanctifies all our moments of happiness.