Marie- Alain Couturier O.P. ( 1897-1954) saw a devastating testimony to the decline of Catholicism in the divorce between the vitality of the visual arts and the pervasive worthlessness of art in the Catholic Church of his time. Devoting his efforts to the reconciliation of living art and Christian art, he was able to get to work for the Church such notable artists as Matisse, Léger, Chagall, Le Corbusier… He asserts the connection between the liturgy and beauty. He observes that the debate between artistic freedom and ecclesiastical constraints may be bypassed in a spiritual perspective, such as that of the great artists. He shows that for the honor of God and the dignity of Christians, Catholicism may thus open up, in the space of worship, to the best of modernity.