MADRID — Pope Benedict XVI said Saturday he would confer one of the Catholic Church’s highest honors on an influential 16th-century Spanish saint, making a surprise announcement during a Mass at the church’s world youth festival.

Benedict drew sustained applause from the seminarians, priests, bishops and cardinals gathered in Madrid’s main cathedral when he announced that he would “soon” declare St. John of Avila a doctor of the church. Such a title is reserved for those churchmen and women whose writings have greatly served the universal church.

There are currently 33 such doctors, including St. Augustine, St. Francis de Sales and St. Teresa of Avila. Pope John Paul II added St. Therese of Lisieux to the list in 1997, the last time one was proclaimed.

St. John of Avila, who lived from 1500-1569, is the patron saint of Spain’s diocesan clergy and was considered one of the greatest preachers of his time. In announcing his decision, Benedict appeared to be giving the priesthood — tarnished by the clerical sex abuse scandal — a model of holiness, intellectual rigor and piety.