For a long time scholars believed that Gnostic Christians were an offshoot from the original Christians and started two or three hundred years after original Christianity.  Recent evidence, especially the Gospel of Thomas, indicates otherwise.  The Gnostics seem to have been around during the first century of the Christian era and may have been the original Christians, predating the Paulists.  
    Most scholars now agree that Jesus was a member of the Essenes, or was at least recognized by them as a spiritual leader.  The small community Jesus formed with his Apostles and disciples that required each to give there money to the community treasury to be used for the good of the community is very much an Essene concept. 
    A major difference between the Gnostics and the Paulist Christians is that the Gnostics emphasized the life of Jesus and following his teachings while the Paulists placed all importance on the death of Jesus and worshiping him.  And it is fairly clear in the Bible that what Peter and James taught was following the teachings of Jesus.  Of course, they could do that since they were there to be taught by Jesus while Paul was not and only had a vague idea of what was taught.  Even today, much of what Jesus taught the original disciples is not known in detail because it was never put in writing.