Syro-Malabar Church in the context of "Syriac Christianity"

The Eastern Catholic Churches or Oriental Catholic Churches, also known as the Eastern-Rite Catholic Churches, Eastern Rite Catholicism, or simply the Eastern Churches, are 23 Eastern Christian autonomous (sui iuris) particular churches of the Catholic Church in full communion with the pope in Rome. Although they are distinct theologically, liturgically, and historically from the Latin Church, they are all in full communion with it and with each other. Eastern Catholics are a minority within the Catholic Church; of the 1.3 billion Catholics in communion with the pope, approximately 18 million are members of the Eastern churches. The largest numbers of Eastern Catholics are found in Eastern Europe, Eastern Africa, the Middle East, and India. As of 2022, the Syro-Malabar Church is the largest Eastern Catholic Church, followed by the Ukrainian Greek Catholic Church.

With the exception of the Maronite Church, the Eastern Catholic Churches are groups that, at different points in the past, used to belong to the Eastern Orthodox Church, the Oriental Orthodox churches, or the Church of the East; these churches underwent various schisms through history. Eastern Catholic Churches that were formerly part of other communions have been points of controversy in ecumenical relations with the Eastern Orthodox and other non-Catholic churches. The five historic liturgical traditions of Eastern Christianity, namely the Alexandrian Rite, the Armenian Rite, the Byzantine Rite, the East Syriac Rite, and the West Syriac Rite, are all represented within Eastern Catholic liturgy. On occasion, this leads to a conflation of the liturgical word "rite" and the institutional word "church". Some Eastern Catholic jurisdictions admit members of churches not in communion with Rome to the Eucharist and the other sacraments.

The Church of the East (Classical Syriac: ܥܕܬܐ ܕܡܕܢܚܐ ʿĒḏtā d-Maḏenḥā) or the East Syriac Church, also called the Church of Seleucia-Ctesiphon, the Persian Church, the Assyrian Church, the Babylonian Church, the Chaldean Church or the Nestorian Church, is one of three major branches of Eastern Nicene Christianity that arose from the Christological controversies in the 5th century and the 6th century, alongside that of Miaphysitism (which came to be known as the Oriental Orthodox Churches) and Chalcedonian Christianity (from which Catholicism, Eastern Orthodoxy and Protestantism would arise).

Having its origins in Mesopotamia during the time of the Parthian Empire, the Church of the East developed its own unique form of Christian theology and liturgy. During the early modern period, a series of schisms gave rise to rival patriarchates, sometimes two, sometimes three. In the latter half of the 20th century, the traditionalist patriarchate of the church underwent a split into two rival patriarchates, namely the Assyrian Church of the East and the Ancient Church of the East, which continue to follow the traditional theology and liturgy of the mother church. The Chaldean Catholic Church based in Iraq and the Syro-Malabar Church in India are two Eastern Catholic churches which also claim the heritage of the Church of the East.

The Words of Institution, also called the Words of Consecration, are words echoing those of Jesus himself at his Last Supper that, when consecrating bread and wine, Christian eucharistic liturgies include in a narrative of that event. Eucharistic scholars sometimes refer to them simply as the verba (Latin for "words").

Almost all existing ancient Christian churches explicitly include the Words of Institution in their eucharistic celebrations and consider them necessary for the validity of the sacrament. This is the practice of the Catholic Church's Latin liturgical rites and Eastern Catholic liturgies, the Eastern Orthodox Church, and all the Oriental Orthodox Churches, including the Armenian, the Coptic, the Ethiopian and the Malankara, as well as the Anglican Communion, Lutheran churches, Methodist churches, and Reformed churches. The only ancient eucharistic ritual still in use that does not explicitly contain the Words of Institution is the Holy Qurbana of Addai and Mari, used for part of the year by the Church of the East denominations, namely Assyrian Church of the East, Ancient Church of the East, and the Chaldean Syrian Church, due to their tradition of using the Holy Leaven. The Chaldean Catholic Church and the Syro-Malabar Church, two of the Eastern Catholic Churches, use the same Anaphora, but insert in it the Words of Institution. However, groups authorized by the Catholic Church to review the Qurbana recognized the validity of this eucharistic celebration in its original form, without explicit mention of the Words of Institution, saying that "the words of Eucharistic Institution are indeed present in the Anaphora of Addai and Mari, not in a coherent narrative way and ad litteram, but rather in a dispersed euchological way, that is, integrated in successive prayers of thanksgiving, praise and intercession."

The Saint Thomas Christians, also called Syrian Christians of India, Marthoma Suriyani Nasrani, Malankara Nasrani, or Nasrani Mappila, are an ethno-religious community of Indian Christians in the state of Kerala (Malabar region), who, for the most part, employ the Eastern and Western liturgical rites of Syriac Christianity. They trace their origins to the evangelistic activity of Thomas the Apostle in the 1st century. The Saint Thomas Christians had been historically a part of the hierarchy of the Church of the East but are now divided into several different Eastern Catholic, Oriental Orthodox, Protestant, and independent bodies, each with their own liturgies and traditions. They are based in Kerala and they speak Malayalam. Nasrani or Nazarene is a Syriac term for Christians, who were among the first converts to Christianity in the Near East.

Historically, this community was organised as the Province of India of the Church of the East, by Patriarch Timothy I (780–823 AD) in the eighth century, it was served by bishops and a local dynastic archdeacon. In the 14th century, the Church of the East declined in the Near East, due to persecution from Tamerlane. Portuguese colonial overtures to bring St Thomas Christians into the Latin Church of the Catholic Church, administered by their Padroado system in the 16th century, led to the first of several rifts (schisms) in the community. The attempts of the Portuguese culminated in the Synod of Diamper, formally subjugating them to the Portuguese Padroado and imposing upon them the Roman Rite of worship. The Portuguese oppression provoked a violent resistance among the Thomasine Christians, that took expression in the Coonan Cross Oath protest in 1653. This led to the permanent schism among the Thomas' Christians of India, leading to the formation of Puthankoor or Puthankūttukār ("New allegiance" ) and Paḻayakūṟ or Pazhayakūr ("Old allegiance") factions. The Paḻayakūṟ comprise the present day Syro-Malabar Church and Chaldean Syrian Church which continue to employ the original East Syriac Rite. The Puthankoottukar, who continued to resist the Catholic missionaries, organized themselves as the independent Malankara Church and entered into a new communion with the Syriac Orthodox Church of Antioch, inheriting from them the West Syriac Rite, replacing the old East Syriac Rite liturgy.

Holy Leaven, also known as Malka (Classical Syriac: ܡܲܠܟܵܐ, pronounced [ˈmalkaː]), is a powder added to the sacramental bread used in the Eucharist of both the Ancient Church of the East and the Assyrian Church of the East and historically in the Church of the East. Both churches hold the Holy Leaven to be one of their seven sacraments. The Syro-Malabar Church in India, which was historically a part of the Church of the East, also uses Holy Leaven to prepare sacramental bread in several churches whereas unleavened bread is also in use. There are two rituals associated with the Holy Leaven: its addition to sacramental bread before it is baked, and the annual renewal of the Holy Leaven itself.

The origin of the Holy Leaven supposedly goes back to the Last Supper. According to various traditions, John the Apostle kept a piece of bread given to him by Jesus and later mixed it with Jesus' blood after his death. This substance was divided between the apostles to be used in preparing sacramental bread ever since and successfully brought to the Christians of the East. The earliest historical mention of the Holy Leaven is from c. 900, and tradition that connects it with the Last Supper is fairly new, dating from the 13th and 14th centuries. It is likely that the Holy Leaven is a symbol instituted to unify congregations by the Patriarchate of Seleucia-Ctesiphon during vast missionary expansion of the Church of the East.