The early medieval Christian literature did not encourage any kind of political intervention among its believers in history. It was not concerned at all with any reform, except for the individual reform of one’s soul. Early medieval literature was not a call to political action, but to the spiritual enrichment of one’s soul.
Justin Martyr’s First Apology may seem like it does promote political reform, but in fact it is simply calling on the emperor to be just. It does not encourage Christians to take any action in political change at all. In fact, it encourages obedience to civil authorities among Christians. Speaking to the emperor:
“Whence to God alone we render worship, but in other things we gladly serve you, acknowledging you as kings and rulers of men, and praying that with your kingly power you be found to possess also sound judgement.”
Justin did not promote political activism among Christians, he simply called upon the civil authorities to exercise sound judgement and to do justice. He called on Christians to obey civil authorities, just not to worship them.
St. Augustine believed that Christians are pilgrims in this world, journeying into the next. He believed that Christians should have little to do with history, for Christianity’s ultimate end exists in eternity with God. He was not concerned at all with social or political reform. He had a somewhat stoic outlook on life, saying that when times are bad you shouldn’t be disheartened, for things will improve; and when times are good, you should pray to God and prepare yourself for tribulation. This outlook does not seem to promote Christians to attempt to change anything in history.
There was not a call to political reform in early medieval Christian literature. It called instead to reform the individual soul, not the political authority. Christianity was viewed as separate from history, and not intermingled with the temporal governments of the world. Christians were encouraged not to rise up against unjust governments, but to obey the rulers as best they could without sinning.