Full communion is a communion or relationship of full agreement among different Christian denominations or Christian individuals that share certain essential principles of Christian theology. Views vary among denominations on exactly what constitutes full communion, but typically when two or more denominations are in full communion it enables services and celebrations, such as the Eucharist, to be shared among congregants or clergy of any of them with the full approval of each.
Full communion is an ecclesiological term for an established relationship between Christian denominations that may be constituted by shared eucharist, doctrine, and ecclesiology. Different denominations emphasize different aspects or define the term differently.
Several Protestant denominations base their idea of full communion on the Augsburg Confession which says that "the true unity of the church" is present where "the gospel is rightly preached and sacraments rightly administered." They believe that full communion between two denominations is not a merger, but rather is when two denominations develop a relationship based on a mutual understanding, respect and recognition of Baptism and sharing of the Lord's Supper. They may worship together, exchange clergy, and share commitments to evangelism and service. For example, groups recognized as being in full communion with the Evangelical Lutheran Church, on this basis, include the Presbyterian Church (USA), Reformed Church in America, United Church of Christ, the Episcopal Church (United States), the Moravian Church, and the United Methodist Church. These churches are not necessarily in full communion with each other, however; each denomination is free to develop its own relationships with other churches. For example, The Episcopal Church, in addition to being a member of the Anglican Communion, is in full communion with the Evangelical Lutheran Church in America, Moravian Church (Northern and Southern Provinces), Mar Thoma Syrian Church of India, Old Catholic Churches of the Union of Utrecht, Philippine Independent Church, and the Church of Sweden.