Jacques Louis David's "Death of Marat" depicts the French revolutionary leader Jean-Paul Marat, who was assassinated while in his bath. The painting functions as a type of altarpiece for the new civic religion by depicting Marat as a martyr to the cause of the French Revolution.
The painting is set up like a religious altarpiece, with Marat in the center, in a pose reminiscent of depictions of Christ on the cross. He is surrounded by symbols of the Revolution, including a bust of Brutus (who overthrew the Roman monarchy) and a French flag.
The painting also highlights Marat's dedication to service and his martyrdom for the Revolution. He is depicted with a quill in his hand, writing a list of enemies of the Revolution, and the knife used to kill him is prominently displayed in the foreground.
Overall, "Death of Marat" functions as a powerful symbol of the new civic religion, inspiring viewers with Marat's dedication and martyrdom for the cause of the Revolution.