This article is the first in a trilogy exploring the concept of resource churches, providing a starting point to develop a comprehensive understanding of their implications for the Church of England. The scene is set by introducing the impact of this recent model of church planting, which has become widespread since the ambitious programme of church development in London in the 1990s. This opening piece examines understanding of what constitutes a resource church and identifies flaws in the existing definition. The existence of resource churches as a distinct model is demonstrated by comparison to concepts of hub churches, megachurches, minster churches and resourcing churches. The need to discuss such distinctions provides evidence that an unambiguous definition for ‘resource church’ is needed. Evaluation of the five core elements in Bishop Ric Thorpe’s definition of resource churches establishes the need for research to determine beliefs and practices of current resource churches.