In 1719 a large- scale campaign of embellishment was undertaken at the parish church of St- Jean- en- Grève in Paris. A new high altar was erected, featuring a canopy with a monumental “Gloire” screen suspended above a sculpture representing the Baptism of Christ. This composition is surprising in a parish that supported the Jansenist cause. An attentive study of the decorative setting reveals its links to the contemporaneous current of “appelants”, which borrowed from the figurist doctrines that read biblical history through the prism of Grace. The appelants saw in the prosecuted Jansenists the announced figures of the Righteous, as was John the Baptist in his time. The theme of Grace placed at the heart of the altar decoration further fortifies the assembly’s conviction of its own divine election.