In spite of a lively debate during the last century, there is still no scholarly consensus about the identity of the opponents in Colossians. The aim of this essay is not to put forward yet another attempt to solve this complex historical problem, but rather to examine how boundaries are drawn between the author and the opponents in Colossians and how similar boundaries are maintained, developed or even created in scholarly historiography. In what Jonathan Z. Smith refers to as the “Protestant Historiographic Myth”, nineteenth and early twentieth century scholars of biblical studies often understood early Christian developments in terms of an original purity that was lost at a later stage. According to this historiographic construction, the essence of Christianity was distorted through interaction with the cultural and religious environment of the Roman Empire and through the incorporation of pagan elements. Throughout this essay, I argue that this essentialist conception of early Christianity has shaped the construction of the opponents of Colossians in scholarly literature. In studies of Colossians, many modern scholars have, problematically, recreated the dichotomy between an original apostolic Christianity and later Hellenized deviations. This legacy of the “Protestant Historiographic myth” is mainly expressed in two ways, either as an opposition between the author’s pure apostolic Christianity and the opponents, who are understood as a syncretistic group, composed of a mixture of various Hellenistic elements, or as a dichotomy between Christianity, as represented by the author, and “religion”, as represented by the opponents.