In Galatians we have a unique circumstance. Paul had assisted in the establishment of the churches in the area but they were changing. In Acts 15, there had been a council that reestablished that the Gospel was for the Gentiles also and they were not under the strict dictate of the Old Testament law but were under Grace. They established the Apostleship of Paul and sent messengers to tell this to the churches. The problem was those who were called the Judiazers. They decided that they were God's chosen and if the church was to be spiritual that they would have to be like them but they could never be them. Paul addresses this gospel as another gospel and that it is specifically not of God nor does it