In August 2026, America Magazine reported that “the liturgy wars are back (and never really left).” The fight Catholics have been having on and off – regarding the Traditional Latin Mass versus the Novus Ordo, Traditionis Custodes versus Summorum Pontificum, and so forth – is nearly six decades old. Yet where the Orthodox are concerned, the original liturgical-canonical divergence goes back more than twenty-five times further.
In the Catholic-Orthodox dialogue, liturgical matters are not usually as contested as are theological questions. (Among the latter are papal authority and the filioque, as I explore in my book Reuniting Rome with the Orthodox.) Nevertheless, differences in rites can hinder the ability of communions to claim the same experience of worship and, at the extreme, can even make it harder for them to identify with one another as fellow Christians. Accordingly, the gradual East-West divergence is worth exploring.
Rome and the East still had more in common than not throughout the early Christian period. Significant differences, however, were appearing by the fourth century.
By the end of the 300s, invoking the Holy Spirit in the Liturgy of the Eucharist was more emphasized among Constantinople and the Greek Churches than among the Western Churches, which instead focused on the words of institution.
Also, during the later 300s the Greek liturgy was uniquely refined: garments like the sticharion (a kind of long tunic), hymnography like the short troparia, and sophisticated vessels were a much more prominent feature of Byzantine rites than of the simpler Latin rites.
Language differences, too, arose: while Rome had initially used Greek, Latin was added in the third century and became dominant by the fourth. To express its faith, the West preferred the pre-Nicene Apostles’ Creed (the “Roman Symbol”); the Greeks adopted the Symbol of Faith produced at Nicaea.
By the end of the seventh century, East and West had diverging prayers, hymns, cadences, and even iconography. And by the 9th century, the West had switched to unleavened bread in the Eucharist, while the East maintained leavened bread. All of this established the Roman rite as distinct from the Byzantine.
Meanwhile, from the fourth century on, East and West also developed starkly different attitudes toward clerical celibacy. Priests throughout the communion of orthodox Churches had been allowed to marry prior to ordination. Rome campaigned, however, to make celibacy universal. By the 700s papal decretals had solidified the Western practice.
On the other hand, the Apostolic Canons, better received in the East, forbade clergy to divorce their wives on grounds of celibacy – on pain of excommunication – and the Synod of Gangra anathematized certain radical proponents of clerical celibacy. At the Quinisext Council of 692 under Justinian II, Eastern Churches limited celibacy to the episcopate.
Those differences could be tolerated for a long time. But in the eleventh century, when cultural contacts became more widespread, the combination of erstwhile isolation and sudden contact dramatically soured East–West relations. Long-endured differences in discipline – unleavened versus leavened bread, fasting, clerical celibacy – came prominently, and painfully, into view.
Patriarch Cerularius of Constantinople wrote combatively to Pope Leo IX in 1053, critiquing the use of unleavened (azymes) bread in the Eucharist and Saturday fasting. And the infamous schism of 1054 was at least in part inspired by disputes over celibacy and azymes.
The list of ritual complaints only grew after the Schism. By 1438, new grievances against the Catholics included “the veneration of three-dimensional figures as well as, or rather than, icons; the multiplication of the forms of monastic life; the use of round, not square, patens for the Mass,” and “the objection that the Roman liturgy (as then constituted) lacks an explicit epiclesis, or consecratory prayer to the Holy Spirit over the bread and wine.”
That last point was still actively being pressed in 1848. The Orthodox patriarchs charged that the “Roman Church [is] not only rejecting from her Liturgical Canon, according to the suggestion of the Schoolmen, the very ancient and Apostolic invocation of the Consecrating Spirit, and miserably mutilating the Sacrifice in its most essential part, but also urgently hastening to cut it out from the Liturgies of other Christian Communions.”
The next major turn was a reform of the Latin rite itself via the Novus Ordo Missae of 1969 following Vatican II. The New Mass’s changes tended to be negatively received by the Orthodox (as well as by many traditional Catholics). Among the modifications were a move from Latin to the vernacular; fewer genuflections; versus populum celebration rather than the ad orientem (an orientation long shared with the Orthodox); Communion in the hand rather than exclusively on the tongue; women as lectors and extraordinary ministers; the alteration or omission of many previous (Tridentine) prayers; new Eucharistic prayers, including an explicit epiclesis; and freestanding altars.
Orthodox theologian Laurent Cleenewerck, himself sympathetic to Catholic-Orthodox unity, admitted: “The liturgical metamorphosis of the Roman Catholic Church. . .widened the gulf” between the two communions. (On the bright side, the Novus Ordo’s addition of an explicit epiclesis indirectly addressed a major Orthodox grievance.)
These developments notwithstanding, one recalls Metropolitan Kallistos Ware’s insistence on the “vital distinction between Tradition and traditions,” where many liturgical matters fall into the latter, less essential category.
Catholic thinkers have made a similar distinction, with Pope Benedict XVI even calling for “mutual enrichment” between varying forms of worship. If Catholic and Orthodox Christians honestly reflect on what elements of the faith are worth ‘warring’ over, perhaps they will better discern – even in the post-Vatican II liturgical landscape – how to observe Christ’s prayer “that they all may be one.”
