Prepare for Sunday Mass: Public and private prayer Each week in OSV Newsweekly, Carl Olson provides a thoughtful, relevant reflection on the Mass readings for Sunday in his "Opening the Word" column. The following is just an excerpt, but you can read the entire column here.

Pope Francis, in Lumen Fidei, his encyclical on faith, noted there are "four elements which comprise the storehouse of memory which the Church hands down: the profession of faith, the celebration of the sacraments, the path of the Ten Commandments and prayer."

The catechesis of the Church has, traditionally, been based upon those four elements. This week's readings have much to say about the first and the latter, and so bring to our attention the relationship between faith and prayer. No discussion of the two can ignore the ancient phrase, lex orandi, lex credendi, which means "the law of prayer is the law of faith." It is immediately evident how the second and third elements — liturgy and the commandments — fit perfectly here, for the public prayer of the Church and the actions of the faithful are the exterior actions that give outward expression to the inner reality of personal faith and private prayer.

This relationship between the interior and exterior realities of faith and the life of the Church are hinted at in the striking story of Moses, extending his hands in supplication for the sake of Israel's warriors. As the younger Joshua leads the soldiers into battle, the man who had directly encountered God in the burning bush and on Mount Sinai, prays on their behalf, his tiring arms supported by his brother Aaron and their companion, Hur. "That is how the Christian community is constructed," wrote Hans Urs von Balthasar about this story, "some fight on the outside while others pray on the inside — in the monastery or a 'private chamber' at home — for those who are fighting."

Read Olson's entire column to prepare for Sunday Mass.

Jennifer Rey is the web editor of Our Sunday Visitor Publishing.