The variety of early Jesus or Christ cult groups has to be surmised from under the veneer of a seemingly mono-origined and unitary Christian movement as exemplified and embodied in the codified mythmaking process that spans the earliest canonical apostolic writings through the early fathers to later heresiological tradition. It is especially the polemics so characteristic of the emerging mainstream tradition that testify to the existence of a variety of early Jesus or Christ cult groups. However, while the names of founders and Christ cult groups proliferate in our sources, the identification and accurate description of the character of these groups is notoriously fraught with difficulty due to the polemically biased and fragmentary nature of the references. This is especially true with regard to cult groups identified as Jewish-Christian. From F. C. Baur to the present, scholarly reconstructions of (what came to be known conventionally as) Jewish Christianity have produced many collections and critical editions of fragments, citations, and the rhetorical and polemical contexts of these citations in mainstream Christian literature, but the precise nature of Jewish-Christian cult group identities and their relation to other strands of tradition (‘orthodox’, Gnostic, etc.) is much more difficult to delineate. The recoverable Jewish-Christian traditions suggest that the interaction and interplay between the later (so-identified) Judaism and Christianity must have been much more complex in the earlier centuries. The thesis explored in this paper holds that there is a broad continuity spanning such utopian Jewish groups as the Qumran Essenes (Doron Mendels), through various types of baptist millennial groups in the ancient Near East. Jewish-Christian cult groups existed on the fringes of these, and in various configurations continued to exist into later Gnosticising traditions. In this paper an attempt is made towards a more accurate social contextualisation of Jewish-Christian groups by starting not so much from what is known about the groups and their leaders from the sources (or the contents of their theologies), but from the opposite end, namely to trace the evidences for a spectrum of ritual practices broadly characterised as water lustrations. The many indications of interpretations of rituals of washing as purification, as well as a framing of these by apocalyptic discourse, enable us to reconstruct a trajectory of doomsday, world-renouncing, counter-cultural groups which reconstruction is informed by cross-cultural comparisons for greater applicability and accuracy in theorising of ‘heterodox’ Jewish-Christian cult groups. As such this paper advances the position that cross-cultural studies in discourse, ritual, and identity formation can greatly assist in drawing more detailed pictures of Jewish-Christian hybrid identity formations. In this, simultaneously, an evaluation is made of the tradition of scholarship on ancient baptismal cult groups from Joseph Thomas (1935), through Kurt Rudolph (1981) to the present day (inter alia, Marjanen/Luomanen, 2005).