As allegiance to Jesus Christ spread across the Roman Empire in the second century, writings, practices, and ideas erupted in a creative maelstrom. Many of the patterns of practice and belief that later become normative emerged, in the midst of debate and argument with neighbours who shared or who rejected that allegiance. Authoritative texts, principles of argument, attitudes to received authority, the demands of allegiance in the face of opposition, identifying who belonged and who did not, all demanded attention. These essays explore those divergent voices, and the no-less diverse and lively debates they have inspired in recent scholarship. Judith M. Lieu is the author of Explorations in the Second Century: Texts, Groups, Ideas, Voices (Brill, 2025). She was Lady Margaret's Professor of Divinity at the University of Cambridge from 2007-2018. She studied at Durham and Birmingham Universities and previously taught at The Queen's College, Birmingham, King's College London (where she was Professor of New Testament Studies, 1999-2006), and Macquarie University, Sydney. From January 2020–June 2021 she was Frothingham Visiting Professor in New Testament and Early Christianity at Harvard Divinity School. She is on the editorial board of a number of journals and series and was previously Editor of New Testament Studies. She is a Fellow of the British Academy (2014) and International Honorary Member of the American Academy of Arts and Sciences (2019). Jonathon Lookadoo is Associate Professor at the Presbyterian University and Theological Seminary in Seoul, South Korea. While his interests range widely over the world of early Christianity, he is the author of books on the Epistle of Barnabas, Ignatius of Antioch, and the Shepherd of Hermas, including The Christology of Ignatius of Antioch (Cascade, 2023).