Byzantine Jerusalem and the potential "ruin" of Christianity

This lecture focused on Byzantine Jerusalem, which was the time after the Romans ban Jews from the city and converted it to a Christian city. Paul goes on a missionary journey off to Rome and there is increasing western expansion of this Jewish sect that eventually became Christianity. We then began talking about how Jesus was a Jew from Jerusalem, who moved to Rome. There was no new testament at the time of Jesus. Before, the Jesus followers referred to themselves as “The Way”, yet later in Antioch once they began to notice a great schism between Judaism and their beliefs, they began to call themselves Christians.
Within Judaism, there was a spiritualization of the faith. It was now portable again and doesn’t have to be tied to a city. Jerusalem and the temple were both destroyed. Jesus predicted the temple destruction. Paul took this new faith, Christianity, to people who weren’t Jews, which caused problems. They faced controversy over issues such as Kosher regulations and had to answer questions such as, must Christians be first circumcised? Paul said no- you don’t have to become a Jew first to then become a Christian. There was also a big debate- did Jesus make the prediction or was it a prediction that was placed into his mouth by the authors of the bible?
Jerusalem is important to Christians because Jesus was said to have been crucified, buried, and raised again from the dead in Jerusalem for the forgiveness of sins of people all over the world. Christian faith became spiritualized away from the temple in Jerusalem – Jesus’s body is a “Temple” that he will rebuild in 3 days (not the physical temple) We then discussed the Tetrarchy and Constantius and his son, Constantine the Great. He realized could use Christianity to unify his entire kingdom. He turned the pacifist, spiritualized religion that did not worry about worldly possessions into a religion that kills/ conquers people in the name of Jesus. He fundamentally changes the way Christianity was practiced.
In 313, the Edict of Milan- Constantine the Great legalizes Christianity
meets with leaders all around uses his influence to come up with a standard orthodox set of beliefs. In 324- holds the Council of Nicaea- created the doctrine of the trinity, theological construct to grapple with the notion that Jesus was fully God and fully Human called the Nicean Creed. C the G made the bishops figure out one right way to have a religious philosophy (which may be why we have so many Christian sects right now). Greco Roman philosophy had an influence and it was an invention of something else, different than what Jesus had taught. Did C the Great “use” Christianity to unite the empire and for his own political gain??? Are the changes he made to the fundamental ideology irreparable? Did he seal doctrines so that it can never be changed such that everybody that doesn’t follow this creed is “not a Christian”?