it was said here that we were still under mosiac law....circumcision was required...Christians changed that....under mosiac law pork was a no-no, Christians changed that too....during the life of Christ....we were not under mosiac law.
"they" were the early Christians known shortly thereafter as Catholics.
They 'changed' NOTHING!
The letter in Acts 15 was written to GENTILES.
The word 'christian' can apply to Jews as well; but the LETTER was written to NON-Jews.