That Rome and its emperor were “problematic” in various ways would have been plain to any Jew or Christian (and not a few pagans) who gave it much thought. On the other hand, the imperial system seems not have served as an especially high-priority ideological or theological target, which is the real rub for many: it is embarrassing to contemporary sensibilities that expect vibrant critique, protest, and resistance to the political realm.
You have adopted the proper course, my dear Pliny, in examining into the cases of those who have been denounced to you as Christians, for no hard and fast rule can be laid down to meet a question of such wide extent. The Christians are not to be hunted out; if they are brought before you and the offence is proved, they are to be punished, but with this reservation – that if any one denies that he is a Christian and makes it clear that he is not, by offering prayers to our deities, then he is to be pardoned because of his recantation, however suspicious his past conduct may have been. But pamphlets published anonymously must not carry any weight whatever, no matter what the charge may be, for they are not only a precedent of the very worst type, but they are not in consonance with the spirit of our age.
This correspondence of the emperor Trajan with Pliny the Younger, the sitting governor of Bithynia and Pontus, has been notorious in Christian circles for a long time. Even Tertullian was commenting on it about a century afterward. Most stunningly for moderns, Trajan advertises the Roman policy of religious repression in quasi-progressive terms: “Yes, my dear Pliny, punish, torture, and execute incorrigible Christians as they pop up, but let’s not have any witch-hunts now; this is the ninth century ab urbe condita, after all.”
Eyes may be rolled justifiably at Trajan’s self-congratulatory little tag—nec nostri saeculi est, such nonsense “doesn’t belong in our age,”—yet it and the rest of the letter tip the Roman hand, at least in this particular period, which comes near the apex of Roman power.
Namely, acute ideological, religious, or theological conformity did not necessarily constitute a political desideratum unto itself, certainly not as it has for many a modern regime. By the far the greater concern taking shape in the emperor’s mind is breakdown in the public social order. To be sure, Christians themselves might threaten that order in certain ways (e.g., their apparent egalitarianism for one, as per the female slaves apparently serving as officers for the community), though Pliny himself in the first letter seems at pains to stress that most of what they appear to be up to is fairly harmless on that front, albeit misguided.