That's not an easy question. The earliest christian records already show huge diversity of thought,doctrine and practice. The authentic works of Paul show him trying to corral Christians to his spin on Christianity revealing that his was not the same as others. He seems to be tolerant of charismatics but not a promoter. Early church father's show a Christianity completely foreign to anything today. There was no Christian Canon,with hundreds of writings, now lost, in circulation. The orthodoxy that eventually dominated spent the next thousand years beating down holdouts and schisms. They never fully succeeded.
I'll sum by reminding everyone that nearly every new sect has asserted they were reestablishing "true" or "original" Christianity