This study examines the mediation effects of forgiveness and gratitude in the association between Korean Christian young adults' religiosity and post-traumatic growth. The participants are 296 Christian young adults in Korea. We hypothesize that the association between young Christian young adults' religiosity and post-traumatic growth is mediated by forgiveness and gratitude. The hypothesized model is tested by structural equation modeling. Results confirm that the religiosity of Christian young adults affects post-traumatic growth through forgiveness and gratitude. Adding a direct path from religiosity to post-traumatic growth significantly improved the model fit, which suggests partial mediation of forgiveness and gratitude in the association between religiosity and post-traumatic growth.