The correct answer is - Christians were no longer persecuted.
Once the Christianity was legalized, the Christians were finally able to leave without any concerns that they will be exiled or killed because of their beliefs. This contributed to a mass acceptance of the religion throughout the continent. It is also worth mentioning, that the Christians instead of promoting peace and tolerance, and learn from what was happening to them, they actually were doing the same to the people that were practicing other religions and were not willing to accept the Christianity, so they massacred and forced million of people to follow their faith.