Religion exists to answer questions posed by people, such as: Why is the sky changing so often. What happens to a person after death. To provide hope during times of emotional disruption. To help identify the group to which a person belongs. To help recognize outsiders (safety). To provide a sense of order and stability within a community. To help children form an identity that corresponds with elders in the group. To explain where and how the group originated (creation myths). And to provide a mechanism for elders to have control and influence on those in the group who are less literate.
The fall of the Roman Empire and the rise of the Catholic Church are really two branches of the same story, as the power was transferred from one entity to the other. From the time of Constantine (AD 312) until the fall of the Roman Empire in 476, the emperors of Rome claimed a certain amount of authority within the church, even though it was disputed by many church leaders. During those formative years, there were many disputes over authority, structure, and doctrine. The emperors sought to increase their authority by granting privileges to various bishops, resulting in disputes about primacy within the churches. At the same time, some of the bishops sought to increase their authority and prestige by accusing others of false doctrine and seeking state support of their positions. Many of those disputes resulted in very sinful behavior, which are a disgrace to the name of Christ.http://www.gotquestions.org/Roman-Catholicism.html
Catholics believe the disciple Peter was the first pope. That was about 540 A D Religion started after Jesus died and in the book of Acts .. The disciples spread the word. That was about 33 A D Approximate dates only
Others can address Catholicism specifically, but this is my best guess about the history of religion in general given the data we have available after five million years of evolution.
Humans, being a social animal, organically developed codes of conduct within our various groups which facilitated order and efficiency within the group.
Then around 500,000 years ago there was a tripling of the size of the neocortex part of the brain--the part associated with religiosity and philosophy. It is supposed that this is about the time that belief in a supernatural world, populated by sentient entities, came about. This filled our need for order by ascribing to these entities control of an otherwise violent and unpredictable world of nature. We gave these beings human characteristics such as love, anger, and jealousy because that was what motivated our actions. In other words, we created gods in our own image.
Christianity started right after the death of Christ. And had nothing to do with Catholics at that time.
26 And when he had found him, he brought him to Antioch. So it was that for a whole year they assembled with the church and taught a great many people. And the disciples were first called Christians in Antioch.