The members of the F.S.S.P. are priests and seminarians who want to express their faith in a specific way. This way is to offer the Mass and other sacraments using the Roman Rite, the way it was before it was changed after the Second Vatican Council. Because of this, the Fraternity uses books of worship from the year 1964, including the Roman Missal, the Roman Breviary, the Pontifical ("Pontificale Romanum"), and the Roman Ritual.