The first 300 years of Christianity were troubled times. As Christians, inspired by their new faith, created churches all over the Roman Empire, they were persecuted and often cruelly executed because they refused to make sacrifices to the Roman gods. The persecutions were not continuous, and some Roman governors made a point of tolerating Christians, but the threat was always there.
One threat they did not face, however, was persecution by other Christians. Christianity was such a fledgling religion that it had no clear hierarchy or even ruling group immediately after the apostles died. It had no orthodoxy and no political power in those early years.
That would change. Heresies led to the terrors of the Spanish Inquisition; the deaths of so-called heretics like Jan Hus (burned at the stake in 1415), Sir Thomas More (beheaded in 1535), and Archbishop Thomas Cranmer (burned at the stake in 1556), to name a few. Those later internecine persecutions could be just as horrifying as Jesus’s crucifixion was.
