How did Christianity change since the crucifixion of Jesus?

A:Christianity has always changed although theologians, especially in the Catholic Church would deny this. The branch of Christianity that eventiually split into the Catholic and Orthodox Churches might not have been the original form of Christianity, or even the most dominant one in early times. Paul's epistles were written long before the gospels and reflect a very different theology than that in the gospels. However, the New Testament gospels were to become the foundation of mainstream Christianity. There were other gospels, but most of these were books of Gnostic Christianity, which was all but eliminated during the purges of the fourth century.

The Church itself evolved from one dominated by wandering preachers such as Paul to a more settled structure, with the creation of the role of bishop, or 'supervisor' in the second century.

The late third century and early part of the fourth were a period in which members of the Church were trying to define the divinity of Jesus. Trinitarianism, the doctrine that would ultimately triumph, held that God the Father, Jesus and the Holy Spirit were three persons in one God, equally divine. Arius, a popular Libyan priest, declared that Christ, while divine, was not divine in the same way as God the Father. Around 318, Alexander, bishop of Alexandria, declared heretical the views of Arius and had him, and the clergy who supported him, excommunicated. In order to fully exclude Arius, Alexander had the Wording that Christ was "of one being with God" adopted at the Council of Nicaea. By the end of the fourth century, Christians in the Roman Empire were required to believe that Jesus was one with God the Father and with the Holy Spirit.

Not content with the Nicene Creed as originally adopted, the bishops of Rome pushed for adoption of a new clause, known as the filioque clause ("and the son"), to be inserted into the Nicene Creed. The eastern Patriarchs disagreed, and therewas an uneasy truce on this matter, until it came to a head and resulted (along with disagreements on ordaining married priests) in the Great Schism of 1054.

Many other doctrines and practices came to be adopted over the centuries, especially in the Western Church, including the notion of original sin and the benefits of purchasing indulgences.

It was not until 1869-70 that the First Vatican Council declared papal infallibility to be a tenet of the Catholic faith. The Catholic Church sought to prove the truth of its claims by the recognition and proclamation of new miracles and visions which in pre-Enlightenment times would have been ridiculed as relics of a superstitious past.