The occurrence of apparently costly and wasteful ritual behavior has long been puzzling for evolutionary scholars. We summarize two models of ritual behavior anchored in the theory of honest signaling. First, the costly signaling theory of ritual (CSTR) is introduced as a solution to the problem of cooperation by allowing ritual participants to signal their commitment to the social norms, which are often fostered by supernatural agents. Second, credibility enhancing displays (CREDs) are proposed as a cultural evolutionary extension of CSTR, which helps to spread the ritual practice and the associated commitment to moralizing supernatural agents. In our view, both mechanisms promote cooperation, and thus help spread and preserve costly ritual behavior. We outline a framework in which CSTR and CREDs can be hierarchically integrated and discuss the outstanding questions related to both CSTR and CREDs, including suggestions for future research.