The extent to which Picasso's work employs spiritual themes and, often, traditional religious iconography, has been most fully explored in The Religious Art of Pablo Picasso (University of California press 2014).
Jane Daggett Dillenberger and John Handley address Picasso’s cryptic 1930 painting of the Crucifixion; the artist’s early life in the Catholic church; elements of transcendence in Guernica; Picasso’s later, fraught relationship with the church, which commissioned him in the 1950s to paint murals for the Temple of Peace chapel in France; and the centrality of religious themes and imagery in bullfighting, the subject of countless Picasso drawings and paintings.