Open communion is the opposite of closed communion, where the sacrament is reserved for members of the particular church or others with which it is in a relationship of full communion or fellowship, or has otherwise recognized for that purpose. Closed communion may refer to either a particular denomination or an individual congregation serving Communion only to its own members.
Generally, churches that offer open communion to other Christians do not require an explicit affirmation of Christianity from the communicant before distributing the elements; the act of receiving is an implicit affirmation. Some churches make an announcement before communion begins such as "We invite all who have professed a faith in Christ to join us at the table."
Open communion is generally practiced in churches where the elements are passed through the congregation (also called self-communication). However, it is also practiced in some churches that have a communion procession, where the congregation comes forward to receive communion in front of the altar; such is the case in the United Methodist Church, the Episcopal Church, most Anglican churches, and some Lutheran churches.
Those practising open communion generally believe that the invitation to receive communion is an invitation to Christ's table, and that it is not the province of human beings to interfere between an individual and Christ. Some traditions maintain that there are certain circumstances under which individuals should not present themselves for (and should voluntarily refrain from receiving) communion. However, if those individuals were to present themselves for communion, they would not be denied. In other traditions, the concept of being "unfit to receive" is unknown, and the actual refusal to distribute the elements to an individual would be considered scandalous.
Most Protestant Christian churches practise open communion, although many require that the communicant be a baptized Christian. Open communion subject to baptism is an official policy of churches in the Anglican Communion. Other churches allowing open communion (with or without the baptism requirement) include the Church of the Nazarene, the Evangelical Free Church, the Church of God, Community Churches, the Presbyterian Church (USA), the Presbyterian Church in America, the Cumberland Presbyterian Church, the United Church of Canada, United Church of Christ, United Methodist Church, the Free Methodist Church, African Methodist Episcopal Church, Foursquare Gospel Church, Association of Vineyard Churches, Metropolitan Community Church, Christian Church (Disciples of Christ), Assemblies of God, the Reformed Church in America, Seventh-day Adventists, Free Will Baptists, Seventh Day Baptists, and most churches in the Southern Baptist Convention. All bodies in the Liberal Catholic Movement practise open communion as a matter of policy. The official policy of the Episcopal Church is to only invite baptized persons to receive communion. However, many parishes do not insist on this and practise open communion. Among Gnostic churches, both the Ecclesia Gnostica and the Apostolic Johannite Church practise open communion. The Plymouth Brethren were founded on the basis of an open communion with any baptized Christian: today, following John Nelson Darby, Exclusive Brethren practise closed communion, and Open Brethren practise open communion on the basis of "receiving to the Lord's table those whom He has received, time being allowed for confidence to be established in our minds that those who we receive are the Lord's." Most churches in the Evangelical Lutheran Church in America practise their own form of open communion, offering the Eucharist to adults without receiving catechetical instruction, provided they are baptized and believe in the Real Presence. The Christian churches and the Calvary Chapel as well as other nondenominational churches also practise open communion. The Uniting Church in Australia practises open communion, inviting all attending to participate.