"As the Christian communities became established, they sometimes faced opposition from Jews and pagans who saw this new faith as a threat and suspected its adherents of engaging in immoral and socially destructive practices (just as new religious movements today are often regarded with suspicion). This opposition sometimes led to local persecutions of Christians; eventually the persecutions became “official,” as Roman administrators intervened to arrest Christians and try to force them to return to the old ways of paganism. As Christianity grew, it eventually converted intellectuals to the faith, who were well equipped to discuss and dismiss the charges typically raised against the Christians. The writings of these intellectuals are sometimes called apologies, from the Greek word for “defense” (apologia). The apologists wrote intellectual defenses of the new faith, trying to show that far from being a threat to the social structure of the empire, it was religion that preached moral behavior; and far from being a dangerous superstition, it represented the ultimate truth in its worship of the one true God. These apologies were important for early Christian readers, as they provided them with the arguments they needed when themselves faced with persecution."
Bart D. Ehrman, Misquoting Jesus: The Story Behind Who Changed the Bible and Why, HarperOne, 2005. 26-27
Miquoting Jesus - Edited Edition (playlist of lecture at Stanford University, 2007)