C.S. Lewis Advent is the first season in the church calendar. Since the 7th century A.D., Christians have included this celebration in their preparation for Christmas Day. Beginning four Sundays before Christmas, its purpose is twofold:. C.S. Lewis Advent is the first season in the church calendar. Since the 7th century A.D., Christians have included this celebration in their preparation for Christmas Day. Beginning four Sundays before Christmas, its purpose…