There are many references to religion throughout the play and the characters have a variety of religious views. For example, Juno is a traditional Catholic and Bentham is a Theosophist.

Mary seems to be more agnostic in her views. She proclaims, “There isn’t a God, there isn’t a God; if there was He wouldn’t let these things happen.”

Many characters resort to prayer in times of distress. For example when Johnny is being dragged out to be murdered, and when Mrs Tancred and Juno are seeking comfort, “Sacred Heart o’ Jesus, take away our hearts o’ stone.”

Johnny takes comfort in religion, despite not seeming to be a very religious person. For instance, he feels safe if the light remains lit under the picture of the Virgin Mary. However, this light could be symbolic of hope and less to do with his faith in the protection of God.

Boyle expresses many anti-religious opinions, seeming to believe that the church does not always have the best of intentions and that people who seem very religious were often not as moral in their everyday actions.

He composes an amusing poem which highlights the hypocrisy of those who attend mass and openly profess a love of God while behaving differently in their lives:

He was not what some call pious - seldom at church or prayer; For the greatest scoundrels I know, sir, goes every Sunday there.

He also believes that "the clergy always had too much power over the people in this unfortunate country". Perhaps Boyle is echoing O’Casey’s own beliefs about a country with little separation between church and state.

Although O’Casey’s Protestant mother brought him up in her own religion, he eventually became an atheist.

Boyle’s voice may be the voice of O’Casey himself on this topic.