Evil features LGBTQ+ characters, most notably Father Ignatius, a gay priest whose internal and institutional struggles are handled with empathy and complexity. Other queer identities appear incidentally without negative framing. The show consistently depicts these characters with dignity, contributing to a net positive portrayal.

The series features a trans woman character, Grace Ling, depicted as a successful businesswoman. Her trans identity is acknowledged factually but is not central to her character's arc or the plot. The portrayal avoids strong positive or negative arcs, presenting her identity incidentally without uplift or denigration, resulting in a neutral overall impact.

The show deeply explores Catholic theology, exorcism, and spiritual warfare, often validating the existence of spiritual evil and the necessity of faith in combating it. While acknowledging institutional flaws, the narrative consistently affirms the spiritual dimension and the virtues of faith through characters like David Acosta.

Ben Shakir, a main character, is a devout Muslim whose intelligence, morality, and faith are consistently portrayed with respect. His Islamic perspective often contributes valuable insights to the team's investigations.

Judaism is respectfully referenced as an ancient Abrahamic faith, often alongside Christianity, contributing to the understanding of spiritual warfare and demonic lore. The show acknowledges its spiritual depth and validity within the broader context of combating evil.