Comparing & Contrasting Eastern Orthodox & Roman Catholics

For more than 1,000 years, there was a single monolithic Christian church. Then, in A.D. 1054, the Pope and the Patriarch of Constantinople excommunicated, creating what is called the Great Schism, during which the major Christian church separated into what became known as the Catholic Church in the west and the Orthodox Church in the east. While there are many similarities between the two denominations, in both belief and practice, each has its distinguishing factors.

The Roman Catholic and Eastern Orthodox churches share many core beliefs regarding Jesus Christ, including his divine and human natures, his virginal birth, his death and subsequent resurrection, and his anticipated return to earth. Both denominations also recognize the teachings expressed in the first seven ecumenical councils.

At the root of the Great Schism between the Roman Catholic and Eastern Orthodox churches was the ways in which the idea of the Trinity was expressed. While the Eastern Orthodox Church emphasized the distinct personhood of each member of the Trinity, the Roman Catholic Church emphasized the Trinity’s unity of essence. This division culminated in the filioque controversy, which was one of the primary theological triggers of the Great Schism. The churches also differed on the perpetual virginity of Mary as well as the nature of original sin.

There are seven sacraments in both the Roman Catholic and Eastern Orthodox churches. These include baptism, confirmation, penance, communion, marriage, holy orders and the anointing of the sick. Today, the practice of these sacraments in both churches is nearly identical in form and content.

One observable difference in ritual between the two groups is seen in communion. While the Eastern Orthodox Church uses leavened bread, the Roman Catholic Church uses unleavened bread. Each holds distinct beliefs about communion as well -- the Eastern Orthodox Church believes that Jesus Christ is mystically present in communion, while the Roman Catholic Church believes that the bread and wine are transformed literally, but invisibly, into the body and blood of Jesus Christ.

Both Roman Catholics and Eastern Orthodox churches use an hierarchical form of church government -- there are several levels of priesthood, including priests, monks, nuns and various levels of bishops. In the Roman Catholic Church, the Bishop of Rome is called the Pope, and he sits atop of the Catholic Church’s organizational hierarchy. Within the Catholic Church, he is considered Christ’s representative as the head of the Catholic Church on earth. The Eastern Orthodox Church is led by patriarchs, and each patriarch is the administrative head over the Orthodox Church in a given geographic region. These patriarchs are considered equals, with none having authority over another. The refusal of the Eastern Orthodox Church to defer to the will of the Bishop of Rome was a primary political factor in the Great Schism.

The Roman Catholic Church has spread around the world, dominating much of Western religion. As of 2012, there were an estimated 1.18 billion Catholics worldwide. The U.S. is home to approximately 60 million Catholics, and the Catholic Church plays an active role in world affairs, including international relations via its own city state, the Vatican.

There are approximately 200 million Eastern Orthodox followers throughout the world. The largest concentration of Eastern Orthodox Christians is in the Russian Orthodox Church, which is estimated to have around 100 million adherents. Orthodoxy has had great difficulty gaining influence in the West, and the number of Eastern Orthodox in the U.S. sits somewhere between 1.5 million and 3 million -- fewer than many Protestant denominations.