The tradition of the Advent calendar is known to have existed in some form since the middle of the 19th century. For Christians all over the world, it has been used as a devotional tool to countdown the days of the Advent season which culminates with the Christmas holiday. Advent calendars have commonly been used for the education and entertainment of children, as scriptural reading guides and as festive seasonal decorations.
Recently, technology has enabled a new twist on this old tradition. Online Advent calendars allow individuals to easily explore scripture, commentary and other content through the familiar form of the calendar. HuffPost Religion has compiled a few of our favorites which offer unique and thoughtful contributions to this Advent season.