Full communion was first reached by provinces of the Anglican Communion with the Old Catholic Churches on the basis of the Bonn Agreement of 1931:
- Each Communion recognizes the catholicity and independence of the other and maintains its own;
- Each Communion agrees to admit members of the other Communion to participate in the Sacraments;
- Intercommunion does not require from either Communion the acceptance of all doctrinal opinion, sacramental devotion, or liturgical practice characteristic of the other but implies that each believes the other to hold all the essentials of the Christian faith.
The principles of the Bonn Agreement are established in the first article, that is, the mutual recognition of "catholicity and independence." A joint doctrinal commission, having weighed the teaching of the two communions, found no impediment to recognition of the wholeness of the Church in doctrine, ministry and sacrament in each other. This is the meaning of the mutual recognition of catholicity. The mutual recognition of indepe-dence of the two communions means that they remain autonomous, that is, neither is subject to outside interference of any other see or communion. The implication is that each communion respects the jurisdiction of the other and avoids any actions that would tend to weaken the faith or loyalty of those in its sister communion, while seeking to cultivate all suitable means for increasing mutual acquaintance and fellowship.
In the second article, these principles are elaborated by means of the mutual admission of members of the other communion to participate in the sacraments. Sharing in holy things creates a visible communion of the faithful, an ecclesial communion. This does not refer exclusively to eucharistic communion, but refers above all to mutual participation in the episcopal consecrations. The ministers of each communion can exchange with each other everywhere and in everything, subject only to canonical disciplinary decisions and agreements. When bishops of one communion take part in the consecration of bishops of the other communion, they acknowledge the duty of mutual care and concern which exists between sister communions in the communion of the One Church.
The third article draws the limits and is intended to avoid misconceptions. The goal is not an absorptive union or the fusion of various churches, but the bringing about of an ecclesiastical community on the basis of unitas in necessaris (unity in necessary things) while maintaining and respecting those possessions of individual churches which do not belong to the essence of the faith.
An implication of this article is that if churches are firmly grounded in what is essential to unity they will find wide room for diversity. The more they agree about unity and are in unity, the freer they will be to accept diversity and plurality. At the same time, we can perceive the outline of a local church that is really one. It is essential that each local church be open to other local churches. The communion within each local church should also be realized between and among the other local churches. The local churches should form a conciliar community among themselves. The bishops, witnesses to their own and other churches' fidelity to the apostolic faith, have the function to articulate communion and serve unity.
Communion in the Church and communion between and among the churches is a dynamic reality, a reality in progress, a reality never perfectly achieved, a reality with which we struggle as we struggle in our personal communion with God and with one another. Though we cannot immediately realize the model of unity which tradition regards as essential, that there be one bishop in a single place, it is of capital importance to achieve the unity of bishops. If such unity cannot be personal, at least it can be collegial.