The Fosters prominently features a married lesbian couple as its protagonists, normalizing a queer-led household. It sensitively explores LGBTQ+ identities and relationships, including a significant storyline about a young gay character's coming out. The show consistently affirms the worth and dignity of its LGBTQ+ characters, portraying their lives with complexity and empathy.

The Fosters features Aaron Baker, a trans man, as a significant character and love interest. His portrayal is affirming, depicting him with dignity, complexity, and agency. The show sensitively explores his experiences, including dating and societal challenges, consistently framing obstacles as external. The narrative validates trans identity and relationships with empathy and respect.

The show portrays Christian characters grappling with traditional beliefs versus modern social issues, particularly LGBTQ+ acceptance. While initially showing conflict, the narrative consistently champions love and acceptance, depicting characters evolving their faith to be more inclusive and affirming, thereby critiquing bigotry rather than the faith itself.