About the Institute for Eastern Christian Studies

The Christian church began in the 1st century with Jesus' followers meeting in house churches in Jerusalem and beyond, led initially by the apostles and elders. By the end of the first century, over 40 communities existed, including in Asia Minor, Rome, Alexandria, and beyond.

Worship was simple: prayer, Scripture reading, teaching, fellowship, and the Lord's Supper, with baptism as the main sacrament. Early Christianity was a Jewish sect until the Council of Jerusalem (c. 50 AD) decided that Gentiles did not need to follow the Mosaic Law, allowing the Gospel to spread widely. This shift was crucial for its survival and growth.

For centuries, Christians were persecuted under Roman law, especially during the reign of Nero (AD 54–68), when they were scapegoated for the Great Fire of Rome. Despite this, the faith persisted through underground worship, martyrdom, and the resilience of small communities.

The Council of Nicaea (325 AD) sought to unify doctrine, affirming the divinity of Christ and establishing the Nicene Creed. Emperor Constantine I's conversion and the Edict of Milan (313 AD) ended state-sponsored persecution, allowing Christianity to flourish. Under Theodosius I, it became the state religion of the Roman Empire.

By the 8th century, the Catholic Church had become a stabilizing institution in Western Europe as the Roman Empire collapsed. Monasteries preserved knowledge, and bishops became central to both spiritual and political life.

The Divine Liturgy, central to Eastern Christian worship, has its roots in early Christian practices and has evolved significantly over the centuries. Known in Greek as Θεία Λειτουργία (Theía Leitourgía), it is the Eucharistic service in most Eastern Christian rites.

The structure of the Liturgy is traditionally divided into two main parts: the Liturgy of the Catechumens, which includes scripture readings and a sermon, and the Liturgy of the Faithful, which focuses on the Eucharist, commemorating the Last Supper.

Three primary forms are widely used in the Byzantine Rite:

• The Divine Liturgy of St. John Chrysostom (5th century) — the most commonly celebrated liturgy throughout the year.
• The Divine Liturgy of St. Basil the Great (4th century) — used on specific occasions, including the Sundays of Great Lent.
• The Divine Liturgy of the Presanctified Gifts — celebrated during Lent, focusing on the Eucharist consecrated previously.

The Great Schism of 1054 was the formal split between the Roman Catholic Church in the West and the Eastern Orthodox Church in the East, driven by theological, cultural, and political differences.

Key theological disputes included the Filioque clause (the procession of the Holy Spirit), the use of leavened versus unleavened bread in the Eucharist, and disagreements over papal authority.

The immediate cause occurred when Pope Leo IX sent Cardinal Humbert to Constantinople to negotiate with Patriarch Michael I Cerularius. When Cerularius refused to recognize the Pope's authority, Humbert excommunicated the Patriarch, and in response, Cerularius excommunicated Humbert and the other legates.

Although the excommunications were lifted in 1965 by Pope Paul VI and Patriarch Athenagoras I as a gesture of goodwill, full communion has never been restored.

As His Holiness Pope Leo XIV and His All-Holiness Bartholomeus continue to dialogue and speak with each other about uniting East and West, we are working behind the scenes as well.

The main thing that we are doing at the Institute is providing retreats for Roman Catholic priests to learn how to offer the Divine Liturgy of the East (St. John Chrysostom liturgy). We are also working with the clergy of the East to invite them to help teach the Roman Catholic priest how to offer the Divine Liturgy.

This will automatically inspire both priests (East and West) to share information with their parishioners so we are all learning about each other and honoring the traditions of both.

We are providing retreats for Roman Catholic priests to learn about Eastern Rites and also learn how to celebrate the Divine Liturgy. We are encouraging priests to become bi-ritual so that they will have at least an "equal" appreciation for the Divine Liturgy as they do for the Mass.

The Orthodox priests, parishes and sketes are open to helping the Roman Catholic priest to learn about the mysteries of the Orthodox faith. As we know, Sacraments in the East and West are both valid and accepted by both. Ecumenism between Roman Catholics and Orthodox is a very powerful thing to do because we both have Jesus Christ from Nazareth on our altars.

We are working with the Vatican and the Phanar to acquire the necessary permissions and support to give Roman Catholic priests the permission to become bi-ritual and work with the Orthodox to learn from each other.

The Orthodox have parishes throughout the world and we are working with His All-Holiness to give permission for the Orthodox to be open to this idea if they are interested in cooperating with this opportunity.