Are the early followers of Christ considered Christians or Jews in today's context? If not, when was the religion created? From sometime after 4 BC and up to and sometime between the destruction of the Second Temple (C. 70) and Council of Nicaea (AD 325), Christians were considered Jewish with Jesus as their leader.  When in this time was the Christian religion created? At some point they obviously were no longer Jews, or we wouldn't have the Judaic religion we have today.  

Secondly, would Jews that were followers of Jesus be considered Christians today?  Given that the divinity of Jesus wasn't "agreed" upon until Synods of Antioch (264 and 269) - arguably it is not universally "agreed" upon today. 

If my dates are wrong, please feel free to correct me
For starters, nobody was really a follower of Christ, as such, until he was about 30 years old (sometime from 27 to 30 AD or so).  At that point, Jesus began teaching in the synagogues and healing in public places.  We read about his first followers in several places, including:


  On one occasion, while the crowd was pressing in on him to hear the word of God, he was standing by the lake of Gennesaret, and he saw two boats by the lake, but the fishermen had gone out of them and were washing their nets. [Miracle elided for space.] For he and all who were with him were astonished at the catch of fish that they had taken, and so also were James and John, sons of Zebedee, who were partners with Simon. And Jesus said to Simon, “Do not be afraid; from now on you will be catching men.” And when they had brought their boats to land, they left everything and followed him.&mdash;Luke 5:1-11 (ESV)


Initially Jesus was considered just another rabbi and miracle worker in the mold of Honi the Circle-Drawer, Hanina ben Dosa and others.

By the end of his ministry, Jesus had been recast by his Jewish accusers of being a rebel against Rome along the lines of the Maccabees, Judas of Galilee and Zadok the Pharisee:


  Then the whole company of them arose and brought him before Pilate. And they began to accuse him, saying, “We found this man misleading our nation and forbidding us to give tribute to Caesar, and saying that he himself is Christ, a king.” And Pilate asked him, “Are you the King of the Jews?” And he answered him, “You have said so.” Then Pilate said to the chief priests and the crowds, “I find no guilt in this man.” But they were urgent, saying, “He stirs up the people, teaching throughout all Judea, from Galilee even to this place.”&mdash;Luke 23:1-5 (ESV)


However, after his death, Jesus' followers remained undeterred and continued teaching and performing miracles in his name.  But they did not seem interested in starting a rebellion:


  Now those who were scattered because of the persecution that arose over Stephen traveled as far as Phoenicia and Cyprus and Antioch, speaking the word to no one except Jews. [Details elided for space.] For a whole year they met with the church and taught a great many people. And in Antioch the disciples were first called Christians.&mdash;Acts 11:19-26 (ESV) 


It's safe to say that by this time, the followers of Jesus had been rejected by the Jewish authorities and there was considerable confusion about their status among the Roman authorities.  The issue is that Rome tolerated Judaism as a traditional religion.  As a sect of Judaism, Christianity was protected from official persecution.  After the Great Revolt, Jews were generally despised by Romans and it's likely that Christians were implicated by association. In 96 AD, Christians were exempted from the "Jewish Tax", so the split was official at that point.

The various councils (after the Jerusalem Council of course) had nothing to do with the split, which had clearly already occurred.