The Liturgy of Saint James is one of the oldest surviving Christian liturgies in existence, dating back to 4th-century Jerusalem. It was historically attributed to James the Just, the brother of Jesus and leader of the early church in Jerusalem. The text of the advent hymn 'Let All Mortal Flesh Keep Silence' is taken directly from this ancient liturgy, serving as a powerful reminder of the early church's profound reverence, awe, and silence before the majesty of Christ. For over sixteen centuries, this liturgy has connected believers across generations in awe of the incarnation.