“Tadao Ando often uses Zen philosophies when conceptualizing his structures. One theme he expresses in this work is the dual nature of existence. The space of the chapel is defined by light, the strong contrast between light and solid. In the chapel light enters from behind the altar from a cross cut in the concrete wall that extends vertically from floor to ceiling and horizontally from wall to wall, aligning perfectly with the joints in the concrete. At this intersection of light and solid the occupant is meant to become aware of the deep division between the spiritual and the secular within himself or herself.”
Wikipedia: Tadao Ando’s Church of the Light