The early centuries of Christianity saw the development of two central streams of belief. In the West, Christianity was centered in Rome; in the East, Christianity was centered in Constantinople. These two streams ultimately led to an organizational split in 1054. While the two groups share certain views, such as a belief in the deity of Christ and the resurrection, they also have some markedly different views.

History of the Schism

It was a difference in views that ultimately led to the schism between Roman Catholic and Greek Orthodox churches. Perhaps the most contentious point of doctrine had to do with the Nicene Creed. The Nicene Creed states that the Holy Spirit proceeds "from the Father." Roman Catholics changed that portion of the Nicene Creed to state "from the father and the Son" in the eighth century. The Orthodox churches didn't accept this change. This seemingly simple distinction in views resulted in the pope excommunicating the patriarch of Constantinople, followed by the patriarch excommunicating the pope.

Views About God and Humanity

Greek Orthodox and Roman Catholics share the most essential views about God. They believe God made everything. They believe God is a Trinity: a single being consisting of Father, Son and Holy Spirit. They also believe that Jesus was God.

Eastern and Western Christians differ in their understanding of humanity, however. For Catholics, the most significant result of Adam and Eve's sin in the Garden of Eden was the corruption of human nature. Catholics believe every human being (with the exception of Mary, the mother of Jesus, as well as Jesus himself) is born with the innate desire to sin. Orthodox believe that every person suffers the consequences of Adam and Eve's sin in that death entered the world, but they don't believe that people are born inherently evil.

Views on the Church

Roman Catholics view the Bishop of Rome as the most important and powerful bishop in the church and refer to him as the pope. The pope is the leader of the worldwide Roman Catholic Church.

The Orthodox churches consider all bishops equal. Orthodoxy is organized into regional patriarchies, which don't submit to a central authority. While all the chief bishops, known as patriarchs, may occasionally get together and make decisions as a council, none rules over the others.

Differences in Practice

The divergent views of Roman Catholics and Eastern Orthodox have produced different practices. For example, Catholics use unleavened bread in the Eucharist, while Orthodox use leavened bread.

Both Orthodox and Catholics venerate or honor the Virgin Mary, but distinctly Catholic views on Mary's role in salvation have led to the creation of rituals like the Rosary that don't exist among Orthodox Christians. Orthodox Christians use prayer beads for a prayer to Jesus rather than Mary.

Orthodox Christians have a long history of using icons (physical representations of saints or of Jesus) in worship, whereas the practice is almost unheard of among Catholics.