Using Josephus and Philo as a starting point, here I discuss how people in the ancient world, including Judeans (Jews), Christians, and others, sometimes expressed the identities of Judean synagogues and Christian congregations in terms of association-life. Although peculiar in some respects, Judean and Christian groups can be studied alongside other associations in the Greco-Roman world. This is part of series 7 (Associations in the Greco-Roman World) of the Religions of the Ancient Mediterranean podcast.