In contrast to a denomination, a communion expresses the organic unity Jesus Christ originally established in His Body, the Church. Rather than emerging from divisions created by historic differences over doctrine and practice, a communion represents return to unity based on the recovery of the essential oneness of the ancient, medieval, and contemporary church.

Standing within the Celtic and Anglican traditions, the Communion of Evangelical Episcopal Churches was created by a convergence of the great historical expressions of faith and practice: the Evangelical, Charismatic, liturgical, and sacramental traditions. The fundamental principles defining inclusion in the Communion are detailed in the Chicago-Lambeth Quadrilateral of 1886.

The four basic statements are:

1. The Holy Scriptures of the Old and New Testaments, as "containing all the things necessary for salvation" and as being the rule and ultimate standard of faith.
2. The Apostle's Creed, as the Baptismal Symbol; and the Nicene Creed, as the sufficient statement of faith.
3. The two Sacraments ordained by the Christ Himself - Baptism and the Supper of the Lord - ministered with unfailing use of Christ's words of institution, and the elements ordained by Him.
4. The Historic Episcopate, locallay adapted in the methods of its administration to the varying needs of the nations and peoples called of God in the Unity of His Church.