Because social status is not the measurement of one rank for any person, but a composite of several social ranks- power, prestige, income, education, purity, family, and local status- the rank of an individual would be the mean of these rankings. More, social rank is most often evaluated not by other people, but by the individual his or her self.
Thus, to say the early Christianity was a movement of the uneducated or the poor and ignorant, as has been described, is to make rather too broad of an assumption- especially since many of our current categories simply do no apply to Roman society.
Rather, what is more pertinent is to say that Roman society produced a great deal of status inconsistency- of an individual's holding unequal rank across several of these categories. This results in status-crossing (as in the case of a freed and subsequently wealthy slave). These are experiences of anxiety that encourage people to work to change society.
Thus, Christianity was able, from its earliest origins, to gather people from a broad spectrum of society- and much prospographic evidence testifies to this.
Christianity, in its cross-section of society, touched and mimicked four institutions:
1. the Roman voluntary association, where wealthy persons acted as patrons for poorer members
2. the synagogue, a local religious institution with ties to a larger world of diaspora Jews
3. the philosophical school, where a key group of trained leaders circulated among Roman cities instructing new converts
4. the Roman household, where members of a family shared intimacy delineated by careful boundaries
The early church itself formed in carefully structured ways. First, Paul especially was certain to speak quite emotionally of Christians as a very special group. He spoke as if they were family, and repeated the terms among various churches, with great respect.
Thus, the church began to supplant previously existing networks of relationships. It began to form the body of Christ, the Pauline term for Christianity borrowed from Greek rhetoric. Early Christian practices such as communion and baptism formed part of a network of shared symbols emphasized each time Christians met together.
This network of symbols set them apart from broader society even as it energized existing relations within the churches. The first urban Christians held the secret meaning of these symbols- a crucified savior, for example- as the very center of their growing faith.