By Fr. George Morelli 
It may not have occurred to some Orthodox Christians that incorporation into the royal priesthood of Christ by the Holy Mystery of Baptism requires us to work toward converting Christians who make up the Apostolic Churches - the Latin and Eastern Catholic, the Eastern and Oriental Orthodox - to the complete fulfillment of the priestly prayer that Christ gave to His Apostles at the Last Supper: "Holy Father, keep them in thy name, which thou hast given me, that they may be one, even as we are one" (Jn 17: 11). Our Holy Spiritual Father St. Theophylact understands this prayer of Christ to mean that His true followers be of "unanimity of thought and will among themselves." St. Theophylact goes on to explain: "Thus Jesus wards off the scandal of division among disciples. If they were to lack unity and oneness of mind, how would their preaching be credible to anyone?" Unfortunately, this scandal is everywhere present in today's world (Morelli, 2010).
Unity among the Apostolic Churches
Those whom we who are convinced of the need for a unity of Christian witness have to missionize are all those who make up these Churches: the Royal Priesthood of the baptized. That is to say, we must reach out to the monastics, the deacons, the priests, the bishops and even the Patriarchs of our Apostolic Churches. The epitome of this oneness will be evident when all can share in Christ's Body and Blood together.
The virtue of zeal
To be effective missionaries we have to cultivate, in cooperation with the grace of the Holy Spirit, the virtue of zeal, that is to say, intensely passionate spiritual fervor for our apostolate.
Let us examine how St. Paul’s instructions to the Romans (12: 9-12) can be a model for our own zealous commitment to Church reunion: "Let love be genuine; hate what is evil, hold fast to what is good; love one another with brotherly affection; outdo one another in showing honor. Never flag in zeal, be aglow with the Spirit, serve the Lord. Rejoice in your hope, be patient in tribulation, be constant in prayer.” Indeed, we must have “a zeal for God” (Rm 10: 2).
Indeed, as part of this we must have a zeal for full re-union of the Apostolic Churches that is so strong that we are motivated to do all we can to make known that disunion is a grievous sin and scandal and a fervent desire, actually as fervent as a demand, for reunion of our Churches, even to the highest levels of our various hierarchies. St. Isaac of Syria (Wensinck, 1923) tells us the outcome when zeal lags. St. Isaac considers zeal a weapon that guides action. "[When someone] casts away the weapon of zeal and becomes as a house without a guardian.... the serene flame of holy knowledge in the soul becomes dark."
A glimmer of hope
There are currently some groups of Apostolic Christians who are working zealously to heal the illness and infirmity of disunion. These groups do not take the place of any of the official national and international dialogues of the various Apostolic Churches. Rather, such efforts are an attempt on the part of all who comprise the 'Body of Christ' to inflame all the Churches to attain a metanoia, a change of mind heart and deed, to re-unite the Churches. One example in the United States is the Society of St. John Chrysostom.i (www.lightoftheeast.org ). Global efforts also are being made. Asia Newsii recently reported on the healing work toward this end of international organizations and individuals in Russia and overseas, such as 'Aid to the Church in Need', 'Christian Russia' and 'Lights on the East.' All must be enlivened by Christ's words: "No one after lighting a lamp covers it with a vessel, or puts it under a bed, but puts it on a stand, that those who enter may see the light" (Lk 8:16).
In the spirit of Christ's words to His Apostles (Mt 28: 19) let us zealously go forth "....and make disciples" - for church unity - "of all nations...." St. Luke (Acts 18: 24-26) tells us about Apollos' fervent and zealous love for Christ. "He began to speak boldly in the synagogue....” Can we do otherwise?
Unity with the Church of Christ
It must also not be forgotten that healing the sin of disunion must go beyond the unity of the Apostolic Churches. Christians of the true Churches of Christ, that is to say, the Churches in unbroken succession from the Apostles, do not form ecclesial communities founded on the teachings of men, but rather on the teachings of Christ Himself, which were inflamed in the hearts of the Apostles by the Holy Spirit at Pentecost. St. Paul's injunction to the Ephesians (4:4-5) must be taken seriously: "There is one body and one Spirit, just as you were called to the one hope that belongs to your call, one Lord, one faith, one baptism...." Christ, right before His Ascension, actually commissioned His followers to extend His teachings to all the world and, by implication, invited all to become members of His Body, His one true Church: "But you shall receive power when the Holy Spirit has come upon you; and you shall be my witnesses in Jerusalem and in all Judea and Samaria and to the end of the earth" (Acts 1:8). A start on such witness can be commenced right now, as suggested by Metropolitan Hilarion Alfeyev.iii The agreement of the Catholic and Orthodox Churches on Sacred Tradition (and Scripture in Tradition), apostolic succession, and the recognition of the Holy-Mysteries provides the common foundation witnessing the major points of moral teaching, including questions of family ethics, human sexuality, bioethics. (Morelli, 2009) In the world today, this means giving testimony by word and deed to agnostics, atheists, humanists, Jews, Moslems, non-Apostolic Christians, pagans, secularists and the un-churched.
What I tell you in the dark, utter in the light; and what you hear whispered, proclaim upon the housetops. (Mt 10: 27)
Blessed Theophylact. (2007). The Explanation of the Holy Gospel According to St. John. (Vol. 4). House Spring, MO: Chrysostom Press
Morelli, G. (2009, November 17). The Power of the Name: Implications for Orthodox Psycho-Theology.www.orthodoxytoday.org/OT/view/morelli-the-power-of-the-name-implications-for-orthodox-psycho-theology .
Morelli, G. (2010, April 30). Toward healing Church schism: Overview and psycho-theological reflection. www.orthodoxytoday.org/OT/view/toward-healing-church-schism-overview-and-psycho-theological-reflection .
Wensinck, A. J. (ed., trans.) (1923). Mystic Treatises by Isaac of Nineveh. Amsterdam, Holland: Koninklijke Akademie Van Wetenschappen.
i The Society of St. John Chrysostom is an ecumenical group of clergy and lay people which promotes Eastern Christianity and Ecumenical Dialogue between the Eastern and Western Churches. It sponsors the Eastern Churches Journal and the annual Orientale Lumen Conference. It has been in existence since 1997 in the United States and for over 70 years in England.
The goals of the Society are to:
- Make known the history, worship, spirituality, discipline and theology of Eastern Christendom.
- Work and pray that all Christians, particularly the Orthodox and Catholic Churches, will attain the fullness of unity which Jesus Christ desires.
- Develop educational programs which present information about the Eastern Churches.
- Organize and conduct pilgrimages and conferences that encourage ecumenical dialogue.
- Contribute to fund-raising activities which support Eastern Christian communities and other programs in need of financial aid.
- Publish books, brochures, and other information which help explain Eastern Christianity.
- Encourage and support the study of the writings and liturgy of Saint John Chrysostom.
- Promote scholarships for the study of Eastern Churches in Catholic and Orthodox seminaries.
iii http://hilarion.ru