There seem to be a lot of logical connections between many Protestant thinkers and Augustine. 

Augustine and the City of God

Mike Bone, Boston University (Fall, 1996)

Augustine began writing City of God as a defense against those who blamed the Christians for the fall of Rome. After Alaric and his Goths sacked the city in 410 AD, some claimed the traditional gods of Rome were angry with the people for abandoning their worship in favor of the Christian religion. In the first half of the work, Augustine argued the implausibility of this thesis based, for example, on the calamities that befell the city long before the birth of Christ. Augustine devoted the remainder of the work to expounding a Christian interpretation not only of contemporary events, but of the entire sweep of human history.

Augustine’s defense was nothing less than a philosophy of history that interpreted events in the lives of nations and people as the redemptive acts of God in history, culminating in the appearance of Christ and the establishment of the church. Augustine formulated this philosophy in terms of an ancient and on-going struggle between two societies: the heavenly city, or city of God, as symbolized by Jerusalem, and the earthly city whose symbol is Babylon. The city of God consists of the elect among humanity and of the holy angels, while the "city of men," i.e., the earthly city, is made up of all those angels and humans who are in rebellion against God. The two are characterized by their respective loves, whether it be love of God or love of self apart from God.

Given such a philosophy of history, one might think that Augustine would have equated the city of God with the institutional church, but such is not the case at all. This is primarily because Augustine viewed the two societies as intermingled to some extent in this life. The image he commonly used to express this mingling of the two cities is from the parable where Jesus compared the kingdom of God to a field of wheat in which an enemy has sown weeds, or tares. While the true church consists of the elect throughout all ages, the church as a visible institution has within it both those whose first love is God and those whose first love is self, i.e., both wheat and tares. Further, there are some outside the church, as Augustine once was, who love God but have not yet embraced Christianity. The two societies will be separated only at the final judgment.

Augustine’s philosophy of history does acknowledge history’s culmination in a bodily resurrection and a final judgment, but his eschatological vision differs markedly from that found in most of the New Testament. Augustine rejected chiliastic, or millenarian, interpretations of the thousand year reign mentioned in the Revelation of John, chapter 20. Instead, he considered the time when the devil is bound and cast into the abyss to be the beginning of this present age of the church when Christ bound the "strong man" (Mark 3). The "first resurrection" of Rev. 20:5 is, then, that of the soul, i.e., regeneration according to faith that takes place in the present life by means of baptism. Further, those who come alive in it and reign with Christ are the elect in the church. Finally, the "thousand years" signified for Augustine the completion of the years allotted to this world, regardless of how long that might be.

Combining these two images, Augustine articulated a view of the institutional church as a kingdom at war. On the one hand, the church even now is the kingdom of Christ and the kingdom of heaven. This age is the millennial reign. On the other hand, it is a church composed of wheat and tares. Therefore, the church is a "kingdom militant," that is, a kingdom at war with the enemies of Christ and with the lusts that rage within its members.

Because of his great reverence for scripture and tradition, Augustine would doubtless have accepted and affirmed every image for the church found in the New Testament. Nevertheless, Augustine’s understanding of the church as composed of wheat and tares to be separated only at the final judgment mitigated the biblical expectation of holy living from each member of the body of Christ. The haustafeln of the Pauline letters, the Petrine application of God’s covenant promises with Israel to the Christian community, James’ assertion that "faith without works is dead": all these attest to the biblical expectation that holiness should reside in both the head and the members of the body of Christ. Augustine’s focus on the church as wheat and tares, however, was a positive move for Christian theology. It allowed him to recognize that God is already at work in a world which, after all, belongs to God by virtue of creation. It confronted the reality that ethical expectation can create a legalism that undermines the church’s defining characteristic of charity, cf. his experience with the Donatists. Then, too, it explained the sociological reality that some who are baptized as infants become truly despicable characters.

Augustine also significantly altered a certain New Testament understanding of the church by interpreting the lurid images of Christian apocalyptic in terms of an on-going present. Such an interpretation flies in the face of the "imminent return" mentality of several of Paul’s letters and, of course, the radical cosmological dualism of apocalyptic literature in general. The positive impact of this creative re-reading of scripture was to make those Pauline letters and the Apocalypse of John more plausible to a fifth century reader. It extended the apologetic strategy already present in II Peter of pointing to a different time sense in the divine: "For a thousand years is as a day to the Lord." Further, it lessened the temptation to engage in pointless speculation as to "the day and hour" (Acts 1).

In spite of the positive impact of both these developments in ecclesiology, I think that in two ways they enervate the very view of church that Augustine espoused, i.e., as a kingdom at war within and without. First, insofar as this approach to eschatology removes the element of cosmological dualism from the church’s self-understanding, it is easier for the church to become just another vested interest. The church is no longer "light in a crooked and perverse generation" (Phil 2). The second is related to this. By positing holiness in the head, i.e., in Christ, alone, the church either relinquishes its mandate to be a change agent in society, or delegates that mandate to a spiritual elite. The church is no longer salt and light, and is certainly not "a city set on a hill" that cannot be hid.