The major theme in the novel is the way people with spiritual or religious leanings function in a largely materialistic world. The Bell is set in the 1950s (a contemporary setting at the time Murdoch was writing) and reflects upon the spiritual awakening that has occurred since World War II. British people suffered numerous bombings throughout the war as well as severe rationings of food and general supplies that persisted for years after the war ended, determining their way of life. This led some to turn toward more spiritual ideas and ideals, as a number of people found solace in faith.

With her depiction of the lay religious community at Imber Court, Murdoch creates a microcosm of all lifestyles. The leader, Michael Meade, is debating becoming a priest, as he has always recognized the spark of the spiritual in himself. James Tayper Pace is more materialistic and sober and less prone to daydreaming, even though he shares religious faith. His role in the community is likewise more pragmatic and rational. Mr. and Mrs. Mark Strafford have come to serve—by serving the community, they believe they serve the higher good of the nearby convent, which they attach themselves to as a lifeline that allows them to exist in both the spiritual and material world.