We design a decision-making scenario experiment on Facebook to measure subjects’ altruism and trust toward attendees of a religious service, a fitness class and a local music performance. Secular and religious subjects alike display significantly more altruism and trust toward the synagogue attendees than participants at the other two venues. By all measures of religiosity, even the most secular subjects behave more prosocially in the religious venue than in the comparable non-religious settings. We also find that secular subjects are just as altruistic toward synagogue and prayer group members as religious subjects are. These findings support recent theories that emphasize the pivotal role of religious context in arousing high levels of prosociality among those who are religious. Finally, our results offer startlingly little evidence for the widely documented religious-secular divide in Israel.