Lacking official recognition and protection Christianity could not be a public religion in the Roman empire. There were no buildings dedicated to public meetings and Christians would have to meet in secret to worship which also made them more prone to be viewed suspiciously. Rumours surfaced that Christians indulged in orgies and cannibalism, the latter being due to the ritual of the lords supper where the bread and wine represented the body and the blood of Christ which was known at that time as the love feast. Orgies though were quite commonplace among the citizens of Rome at that time.
We have some early recorded documents dating from the late first and early second centuries particularly a manual called the Didache (meaning Teaching) explaining that worship took place in a private house rather than a public place. Justin Martyr also describes early Christian worship services which included the baptism of new believers, worshipers greeted one another with a kiss, bread and water were brought to the president (The word priest is not used) who offered a Eucharistic prayer ascribing glory to the father son and holy spirit. Sunday was to be known as the Sabbath rather than the Jewish practice of Saturdays, because Sunday was considered the first day of creation and the day on which Jesus rose from the dead. Only baptized people were allowed to attend these meetings. Some readings are given from the memoirs of the apostles, writings of the prophets and prayers were offered before the Eucharist celebration. Gifts were then brought to the president for distribution to those in need and the deacon took the bread and wine out to those who had been unable to attend. The service ended with a rousing Amen.
Funeral rites were important to the Romans who tended to cremate their dead and place the ashes in carved urns. Christians however insisted on burials in keeping with the events following Christs crucifixion. Because Christianity was an underground movement Christians constructed underground burial sites called catacombs by carving tunnels and niches into the walls in which to place the dead bodies as they waited for the resurrection. When Christianity was legalised in the 4th century the catacombs fell into disuse because Christians were then able to provide funeral rites openly without fear of persecution.
Early Christianity was not well organised mainly because it was difficult to organise services while the Christian movement was illegal as individuals were subject to cruel punishments so leaders were not able to offer a visible central point of control. The terms Bishop (Episcopas) Deacon (Diakonas) and elder (Prysbeteros) were all terms that were used because they would all have been used in the large houses of the day and because any new titles may have attracted the unwanted attention of the authorities. Christianity took on domestic terms because meeting places were called households of faith. There seemed to be no particular hierarchy and although a bishop may have been senior in some way, the term bishop was used merely to describe the leader of a house. Hierarchy only began to develop when Christianity became the official religion of the Roman empire. Christian communities met more on the lines of a club, society or independent association.
Summary and References from Christian history- An introduction- Alister E.McGrath