Why did Christianity spread in the Roman Empire with such ease?

The swift
spread of Christianity throughout the Roman Empire had a number of different causes. The most
obvious event was the conversion of Constantine to Christianity. Emperor Constantine also made
it legal to practice the religion and ended the practice of persecution that had been so common
in Rome. The Emperor Theodosius made Christianity the official religion of the state, which also
greatly aided the spread of Christianity. Despite the importance of these two emperors,
Christianity had already taken hold in the many areas controlled by Rome. It is estimated that
roughly ten percent of the population practiced Christianity as early as the Fourth Century. How
did the religion spread so ferociously despite the persecution of its believers?

It can be said that the religion was tailored for the masses. Much of the message of
Jesus was directed at the poor and destitute. The promise of an afterlife for believers was
attractive and the stories of miracles also intrigued many. Christians also sought converts and
those that died for the faith attracted attention amongst the masses.

The
relative ease of travel throughout Rome was another reason the religion spread. The Roman road
system allowed the movement of goods and ideas. The teachings of Christianity spread to millions
of people as a result. The peace provided by the Roman army allowed ease of travel along these
roads.