History tells us that Constantine became a catechumen after a symbol of Christ helped him win a crucial battle. Then, he waited until he was on his deathbed to be baptized. Baptism was a major commitment; until he knew his end was near, he didn't want to assume the demands of Christianity. He seemed a bit like King Ahaz, who rather ironically told Isaiah that he would not "tempt" God by asking for the sign that God had already offered him. Ahaz didn't want a sign that might require his conversion.
The fourth Sunday of Advent abounds in signs, one long misinterpreted, one hard to read, and one presented as a living example. They all focus our celebration of Emmanuel, God with us.
First of all, the sign of Ahaz: "The young maid shall conceive and bear a son … Emmanuel." Who could ask for a better Christmas prophecy! Unfortunately, Isaiah had no intention of speaking about a messiah like Jesus. The prophecy referred to his own time and a son to be born to Ahaz, a wicked ruler who was not particularly interested in an heir who would be a living sign of God's presence among the people.
Paul began his Letter to the Romans, our second reading, with a 90-word sentence in Greek. (Pitying readers, translators have added more punctuation.) Falling all over himself with the emotion of the total message, Paul introduces himself, his vocation and his Gospel to the Romans, framing his conversion and theirs in in the context of Christ's incarnation and resurrection. Paul's sign was their life-changing common call to faith.
Finally, we hear Matthew's account of the "birth of Jesus Christ." This selection coming just after Matthew uses Jesus' genealogy to show how salvation history reached its high point in Jesus, who Matthew immediately identifies as the Messiah. The word translated as "birth" can also be translated as origins, or creation. Seen in context, we realize that Matthew is not talking about a nativity, he's chronicling God's ongoing outreach to humanity. (Luke is the only evangelist to give us details about Jesus' birthday.)
As soon as we have grasped the messianic significance of Jesus' origins, Matthew reminds us that Emmanuel's coming will feel problematic and conflictual. Theology and spirituality aside, there is a very real, practical problem: Mary is pregnant with a child Joseph did not engender. This is Joseph's test, his moment to confront the paradoxical dilemma that Paul calls "the obedience of faith." Joseph has to decide between righteous obedience to God's covenant in the law and the command of an angel who came to him in a dream.
The key to the angel's message is the words, "do not be afraid." Joseph would have recognized those words as God's reply to Abraham when he was worried that God's promises had been a fantasy and he would die childless (Genesis 15:1). Joseph had discerned that he should divorce Mary quietly, but, as one who had often prayed Psalm 127, he realized that the plan was not to be his, but God's. Risking faith over the security of the law, Joseph adopted what he believed was God's plan. He adopted the unborn child as his own and remained faithful to Mary in spite of everything that seemed obvious.
Joseph received no irrefutable sign. All he had to go on was the dream and the intuition that God's future promised more than he could accomplish. With that, Joseph becomes a sign for the future. The law and tradition offer guides, but, as Pope Francis teaches, the word of God is free and unruly, accomplishing "what it wills in ways that surpass our calculations and ways of thinking" (Evangelii Gaudium, 22).
Today's readings are designed to remind us that encountering Emmanuel, God with us, is both very demanding and immensely surprising. Like his father Abraham, Joseph ventured into the risky unknown, trusting that, no matter what it would cost him, God and the divine promises were bigger and better than his wildest imaginings. Acting from the risky obedience of faith, Joseph adopted God's plan. Staking his life on God's promise, he anticipated the mercy his adopted son would offer; he took Mary into his home and accepted the fact that his life would never be what he expected.
Advent calls us, like Joseph, to be ready for unexpected, often unhoped-for, change. God offers, as Paul says, more than we could ever ask or imagine. Perhaps the lesson of Advent is that it's not so much we who are waiting, but God who comes to our door and appears in dreams, asking, "Will you, like Joseph, adopt my plan? Will you make room for Emmanuel in ways you've never imagined?"