Jesus of Nazareth is the central figure of the Christian religion, a savior believed to be both God incarnate and a human being. He is also known as Jesus Christ, the term "Christ" meaning anointed or chosen one. Most of the details of his life are unclear, and much of what is known about his life comes from the four Gospels of the Bible. The Gospels tell the story of Jesus's auspicious birth in a stable in Bethlehem, and then of his life as an adult, a teacher with miraculous powers who foretold his own death to his closest followers, called apostles. Jesus, betrayed by the apostle Judas, was crucified by the Romans, and his resurrection three days after his death was taken as proof of his divinity. The date of Jesus's birth to Mary is celebrated each December 25th as Christmas Day. The occasion was used as the base year for the modern Christian calendar, though researchers now believe that earlier estimates were inexact and that Jesus was actually born between 4 B.C. and 7 B.C. The date of the crucifixion is now marked as Good Friday, and the resurrection celebrated as Easter.
The Catholic Church bases its doctrines about Jesus on a variety of sources, including the Bible, as interpreted by the Church, and through Church Tradition. The Bible contains stories about the life and teaching of Jesus, and Church Tradition consists of the major creeds, Church councils, and teachings of the Catholic Magisterium about Jesus. These sources tell us that Jesus Christ is the Messiah (or Christ) of Israel, and God himself in the flesh. God the Son, the second person of the Blessed Trinity, became human in the historical, fully human figure of Jesus, which was the prime act of love by a loving God (John 1:1, Hebrews 1:8, Titus 2:13, 325 AD, 381 AD). This unity of divine and human natures in one person, Jesus Christ, is not something that we are able to fully explain scientifically. We accept the paradox, the mystery, and ultimately believe by faith that Jesus is fully human and fully God. Thus Catholics believe that Jesus is a single person, and that the human and divine in Jesus are fully and completely united, not divided in any way. When Jesus healed, both the human and divine nature in Jesus healed. When Jesus writhed in pain, God and human writhed in pain ( 451 AD). Is this shocking to the rational mind? For most of us, yes. The paradox of the God of the cosmos becoming human, and taking on all of our humanity (body odor, pain, suffering, and death included) is incomprehensible to the purely mechanistic mind, and certainly was in ancient times as well. Jesus also has two wills, human and divine, and they, like his two natures, are united as one, neither diminished ( 680/681 AD).
All of this information about Jesus is not simply theological or philosophical speculation, since it relates to our salvation. Who Jesus is, and what he did, essentially determines whether or not he had the power to save us. Had Jesus not been God, he could not have saved us from our sins, for only God is able to give salvation. Jesus' death also played an important role in our salvation. According to the Catholic Catechism
Justification has been merited for us by the Passion of Christ who offered himself on the cross as a living victim, holy and pleasing to God, and whose blood has become the instrument of atonement for the sins of all men ( 1992).
However, in addition to Christ's sacrificial death, as mentioned above, other realities are involved in our redemption. In a way, who Jesus was and everything he did played a part of our redemption: his incarnation, death, resurrection, and ascension. Part of our redemption is becoming more and more like God, called "theosis" in the Eastern Churches. This process of redemption and reconciliation to God is call "the atonement."
- The Great Schism: Eastern Orthodoxy and Roman Catholicism
Unfortunately, by the eleventh century A.D. the differences between East and West became great enough to cause a separation of the One Holy Orthodox Catholic Church. The Eastern Church became known as the Eastern Orthodox Church and the Western Church became know as the Roman Catholic Church, for it was governed and administered by the bishop or Pope of Rome. Again it must be emphasized that there were many factors besides theological ones which led to the schism of the one Christian Church. However, some theological issues which were promulgated by the Western Church were never and are not to this very day accepted by the Eastern Church such as: the infallibility of the Pope of Rome on matters of Church doctrine, the universal jurisdictional authority of the Pope of Rome, the doctrine of Purgatory, the immaculate conception of the Virgin Mary, the unauthorized addition of "and the Son" to the eighth article of the Nicene Creed, et. al.