Communion is a term in the Christian vocabulary that has a number of special uses. The one most frequently met is its attachment to the sacrament of the Lord's Supper, sometimes called the Eucharist, or, in ordinary Roman Catholic usage, the Mass. This central act of Christian worship is widely known as the "celebration of the Holy Communion", emphasizing that the act of receiving the consecrated elements is the climax of the worshipers' participation in the liturgy. "Communion", therefore, may refer to the sacramental service of worship or to the reception of the elements therein.
Usages in Holy Communion vary among the Christian churches almost as widely as do doctrines or convictions in respect to the full meaning of the sacrament, the manner in which the Lord's presence is apprehended by the participants, or the spiritual benefits conferred thereby. Whatever their differences, however, there are few Christians who are not faithful to the command of Jesus at the Last Supper: "This is my body which is broken for you. Do this in remembrance of me" and "This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me". (I Corinthians 11:23-26). Bread and wine are the elements of Holy Communion, though a number of Protestant churches use grape juice in place of wine.
The Roman Catholic Church normally administers the elements to the people in one kind, that is, the consecrated bread alone. Protestants returned to the more ancient use of both kinds in the peoples' communion, though there is variety in the manner of receiving. In Anglican churches, for example, the chalice is used for all communicants at the altar rail, but some Protestant churches use individual communion cups that are distributed throughout the congregation. In Eastern Orthodox churches communion is given in both kinds by intinction; that is, fragments of the consecrated bread are placed in the chalice, and the two species are administered together with a spoon.
In those churches where reception from the chalice is practiced, a method of intinction is sometimes employed in which the communicant or the officiating clergyman touches the bread to the consecrated wine in the chalice.
The word "communion" is also used to denote a group of churches bound together by common faith, principles of church order, and ways of worship. The Anglican churches throughout the world are thus often spoken of as the Anglican Communion. An extended use of the term that derives from this application is made when it is said that certain churches are "in full communion" or "in intercommunion". These churches permit the adherents of each to receive the sacraments in the other. This practice is also sometimes called "table fellowship".
In the phrase "The Communion of Saints", which appears in the Apostles' Creed, the word refers to the union of all Christian souls as members of the mystical Body of Christ. In traditional Roman Catholic thought this includes all on earth, in purgatory, or in heaven. This conviction of the unity of all Christians in Christ can be expressed more simply as the fellowship of all believers, living and departed.