Forgivingness is an important virtue in interpersonal relationships. This panel study investigated the directional relationship of forgivingness with religiousness, pessimistic attributional style, and social cynicism using data collected from 4,829 Chinese adults. Additionally, 51 nonbelievers who became Christian believers (converts) within a 3-year timeframe were prospectively compared with a matched sample of nonbelievers. Results suggested a directional effect of religious conversion on forgivingness. In contrast, religiosity social axiom was neither an antecedent nor outcome of forgivingness as indicated in a cross-lagged analysis. Of note, pessimistic attributional style was both an antecedent and outcome of unforgivingness, which also fueled subsequent social cynicism. These relationships were invariant across the Christian and the nonreligious groups, thus suggesting generalizability. This study advances understanding of the nomological network of forgivingness and sheds light on how this socially desirable virtue can be enhanced.