Going along with Peacfulpete, if you read about the arguments concerning Jesus at Nicea 325 you’ll find they could of answered some of these issues by just reading the gospel of John and possibly some of the other New Testament writtings. This leads me to believe that the gospel of john and other New Testament writtings were not written until after this meeting.
Many scholars believe that a good portion of the New Testament was written by Eusebius.