From the article Religious art is about being human at Guardian by Sophia Deboick:
'Even the most iconic of religious artworks can have profound meanings for the nonbeliever. Grünewald's depiction of the crucifixion on the Isenheim Altarpiece is one of the most wrenching in the history of western religious art, showing an apparently rotting Christ, his flesh pierced with thorns, his feet and hands horribly contorted. Here is an image that, for the Christian, emphasises the extreme sacrifice of the crucifixion, but here is also human suffering, disease and grief (powerfully depicted in Mary Magdalen's anguished hand-wringing and the Virgin's swoon). That it was painted for the hospital chapel of St Anthony's monastery in Isenheim, where those suffering from ergotism-induced gangrene were treated, underscores that it had more to say about body than soul to its intended observers.
Religious art, arguably like religion itself, ultimately deals with the trials of being human, and this is something those of all faiths and none can share in. The pope is right when he says that "art can express and render visible humanity's need to go beyond what one sees, revealing a thirst and quest for the infinite", but that "infinite" is the unfathomable in ourselves, whether we call that "God" or not.'