The City of God was completed three years before Augustine died. The Barbarians overcame this Roman province of Africa later in the century. They reached Hippo in 430, the year of Augustine’s death. Christianity was wiped out. In this case at least Tertullian’s saying that the blood of martyrs is the seed of the church was inapplicable. The retrenchment of Rome from its outer provinces, the division of the empire into two halves centred on Rome and Constantinople, accentuated the importance of Rome in the West, and this was underlined by the Crusades, leading to the Holy Roman Empire of which you and I are heirs. The rest is history.
[A]ccording to our religion and the scriptures, the citizens of God, as long as they are pilgrims, and in the way of God, do fear, desire, rejoice and sorrow. But their love, being right, straighten all these emotions. They fear eternal pain, and desire eternal joy. They sorrow for the present, because they sigh in themselves, waiting for their adoption, even the redemption of their bodies. They rejoice in hope, because that shall be fulfilled which is written. They fear to offend, and desire to persevere. They sorrow for sin and rejoice in doing good….And as they are strong or weak, so do they desire or fear to be tempted: rejoicing or sorrowing in temptation. (City of God, 14.9)
Wretched then are they that are strangers to that God, and yet have those a kind of allowable peace, but that they shall not have for ever, because they used it not well when they had it. But that they should have it in this life is for our good also; because during our commixture with Babylon, we ourselves make use of her peace, and though faith does free the people of God at length out of her, yet in the meantime we live as pilgrims in her. And therefore the apostle admonished the Church to pray fore kings and potentates of that earthly city, adding this reason, ‘that we may lead a quiet life in all godliness and charity’. (City of God, 19.26)
This is an extract from a paper given at the Affinity Theological Study Conference, 2017