The English Reformation of the mid-sixteenth century was characterised by a vigorous public discourse of controversy, mediated by the still-novel printing press. On the one side were those – the godly – who favoured reformed religion; on the other were those – generally exiles – who held to increasingly embattled Roman Catholicism. This chapter compares the outputs of two communities of practice – one Protestant, one Catholic – from a key period in the Reformation’s history: the 1560s. It demonstrates how both sides developed distinctive, ideologically-charged lexicons of theology and insult. It also shows how reformers in particular deployed a coded English vocabulary, including words not usually seen as part of the semantic field of religion, to mark their distinctive discourse community.