Why do frescoes found in roman catacombs usually picture?

Frescoes found in Roman catacombs typically depict Christian themes, such as biblical scenes and symbols, reflecting the beliefs and hopes of early Christians regarding salvation and the afterlife. These artworks served both a decorative and didactic purpose, providing comfort and spiritual guidance to the deceased and their families. Additionally, the imagery often emphasized resurrection and eternal life, aligning with the Christian doctrine of hope in the face of death.