A sanctuary is a holy place
When used in the context of Catholic church interiors, the term “sanctuary” traditionally refers to the area where the altar table sits and from which the priest celebrates the Eucharist. More specifically, The Catechism of the Catholic Church defines it as “The part of a church set apart for the principle rites of worship.” The sanctuary is typically located at the front of the church, and in the case of my parish and many more of its era, at the end of a long nave where the assembly sits. While it may be appropriate for this section of the church to be treated and thought of differently, its designation as a place separate from the faithful who present themselves at the table is not the intended use here. The word sanctuary, as used in “Art in the Sanctuary” presumes a broader definition of a holy place for all the faithful who gather. When understood this way, the place of sanctuary encircles the whole Body of Christ.
 United States Conference of Catholic Bishops. Catechism of the Catholic Church. 2nd edition. (Vatican City; Washington, D.C.: USCCB Publishing, 2000) 898.