O Wisdom! O Lord of Light! O King of the Nations! Since at least the 12th century the magnificent “O antiphons” have traditionally preceded the chanting of the Magnificat at Evening Prayer on the seven days leading up to Christmas Eve. The antiphons in the Liturgy of the Hours are like keys to the psalms and canticles; each one opens a door into a slightly different place in its corresponding text. But the “O antiphons” are far more to me than a familiar litany of titles for the Messiah. As these antiphons slowly unfold in the last days before Christmas, I find in them both invitation and challenge.