Saint-Sernin was built in the fervour of the development of pilgrimages in the 11th Century. Relics (the bodily remains of a saint, or objects that belonged to a saint) are venerated as things close to a saint during his or her life on earth. The more relics a sanctuary owned and exposed to view, the more pilgrims it attracted. The pilgrim Route of Saint James slowly became a kind of rosary of pilgrimages, with Saint-Sernin occupying a major position in it.
The Christian faith is not an ideology. It is an experience lived, with God. Relics recall the work of grace in the lives of the saints. They were people who allowed Baptism to unfold and flower in them. The veneration of relics expresses the knowledge that the human body, even in its weakness, is the Temple of the Spirit. Pilgrims manifest, through their undertaking, their desire to be pleasing to God, and they ask the saints to intercede for them as they go forward.