What was the status of christianity in the roman empire during the first three centuries a. d.?

The early Roman empire saw Christianity as a sort of cult that was potentially dangerous. Christians practice the idea of only one God and therefore did not participate in certain pagan practices such as the Caesar worship which the Romans viewed as disloyalty to their rulers thus the persecutions against  Christians began. At the end of the first century Christianity severed all ties with Judaism and established itself as an independent religion. 

Buddhist missionaries spread the new faith, first to sri lanka.