Introducing sustainability practices amongst the adult population has had a history of mixed success. One problem has been identifying a meaningful target group that has a collective identity based on something more psychologically meaningful than age, residential location or even occupation. encouraging sustainability practices among a social group whose values and beliefs supposedly incorporate a concern about the earth should have a significantly higher chance of success. This paper will report on a recently introduced project called Tread Lightly in the Diocese of Guildford (Surrey, UK). The Tread Lightly Programme aims to encourage church groups (of all denominations) think about, assess and act to reduce the environmental footprint of their churches. Tread Lightly takes groups through a ten stage process from forming an action group to initiate change, identifying the church's environmental effects by means of an environmental audit, developing an environmental policy in response to the findings and implementing an action plan to change consumption and waste practices within a spiritual and theological context. The paper will describe the Tread Lightly Programme in detail and assess feedback from the early stages of the implementation of the pilot programme.