As a kid, my family participated in Advent through a liturgy that I assume my father created, drawing from various sources and scripture. Each Sunday night in Advent, we would turn off the fluorescent bulbs in our dining room, light a candle on the Advent Wreath, and pray together through Scripture. As we did this we traced the biblical prophecies of the coming Messiah, culminating in their fulfillment in the birth of Christ. From the first time we did this on, something about the liturgy—and especially the Church Year—stuck with me.
There are a multitude of reasons that all Christians would benefit from engaging with the Christian calendar, but here are the Big Three for me: