The earliest Christians did not have church buildings. They typically met in homes. (The first actual church building so far found is at Dura Europos on the Euphrates, dating about 231.) They did not have public ceremonies that would introduce them to the public, and they had no access to the mass media of their day. So, how can we account for their steady and diverse expansion over the first three centuries?

After the Apostle Paul, we do not run across many "big names" as missionaries in the first few hundred years of Christian history. Instead, the faith spread through a multitude of humble, ordinary believers whose names have been long forgotten.

Early Christianity was primarily an urban faith, establishing itself in the city centers of the Roman Empire. Most of the people lived close together in crowded tenements. There were few secrets in such a setting. The faith spread as neighbors saw the believers' lives close-up on a daily basis.

And what kind of lives did they lead? Justin Martyr, a noted early Christian theologian, wrote to Emperor Antoninus Pius and described the believers: "We formerly rejoiced in uncleanness of life, but now love only chastity; before we used the magic arts, but now dedicate ourselves to the true and unbegotten God; before we loved money and possessions more than anything, but now we share what we have and to everyone who is in need; before we hated one another and killed one another and would not eat with those of another race, but now since the manifestation of Christ, we have come to a common life and pray for our enemies and try to win over those who hate us without just cause."

In another place Justin points out how those opposed to Christianity were sometimes won over as they saw the consistency in the lives of believers, noting their extraordinary forbearance when cheated and their honesty in business dealings.

Adapted from ChristianHistoryTimeline.com.