Paul Avis in this, his latest work, draws firstly on the missiological insights of Karl Barth and the Second Vatican Council concerning the mission Dei, relating this theme directly to the tasks entrusted to the Church in 'The Great Commission' of Matthew 28: the ministry of the Word, the celebration of the sacraments and the exercise of pastoral responsibility. Avis shows how Christians share in the ministry of Christ himself. Secondly, he carries the argument forward, clarifying the much-abused term 'ministry' and offering a more rigorous and somewhat controversial definition of ministry: work for the Church that is mandated by the Church, and explicitly related to its core tasks. Ministers therefore represent both Christ and his Church. Finally, Avis applies his insights to ordained and lay ministry, and offers a cogent answer to the question: What difference does ordination make? The book concludes with an agenda for the reform and development of ministry in the light of the arguments advanced.