In contrast to its original name, Ecclesia Reformata, ecclesiology did not develop into a major theme within the Reformed tradition. Notwithstanding the undeniable schismatic tendency and the ecclesial embarrassment about disunity, the unity of the church did not rise to prominence as a theological topic. This volume challenges this traditional low-key attitude towards the unity of the church. It investigates theological aspects that contributed to a weak sensus unitatis, and explores approaches that remedy the disease of division. It discusses the role played by scripture, the sacraments, confessions, and discipline; it searches for the best theological practices within other Christian traditions; it links the unity of the church to the unity of God and reformulates the nature of the church.