The first foundation of Christendom is that reality is grounded in God. Even if one locates the foundation of political order specifically in natural law, this law reveals the God who created nature and mankind in the first place. Second, the nature and history of mankind climax in the public personage of Jesus Christ, who at His ascension, claimed that “all authority in heaven and on earth” had been given to Him (Matt. 28:18). All authority has always been subject to and grounded in God. Now, according to a providential and historical exercise of that authority, God Himself has identified the risen Prophet, Priest, and King of our world to be over all other authorities. He is the King of Kings. All things are His inheritance (Psalm 2).
That’s the basic picture. Another way of getting at this would be to ask whether or not all persons are obligated to acknowledge Christ as their Savior and King. It would seem that this is obvious in New Testament revelation (Acts 17:30). Are all persons obligated to do all that they do for the glory of God, which includes the glory of the risen Lord? It would seem that they are (1 Cor. 10:31). If so, it would seem to follow that in all of our exercises of power and in our vocation, we are to be motivated by and in submission to the greater authority of Christ the Lord. This cannot but include all civic representatives in whatever public office.
Cannot the public exercise of neighbor loving, nevertheless, be motivated by Christ without explicitly invoking His dominion in the public sphere? Perhaps. But consider, what governs whether or not this ought to be the case? If such an order were the case, who would establish a coherent ground for this limitation of the public sphere and of public power? From what I can tell, the only binding normative (rather than historically and pragmatically accidental) ground for this limitation would be precisely that God’s authority, and Jesus’ kingship actually requires or at least permits this sort of public reserve – perhaps because such is in accordance with the natural law which is affirmed rather than negated in the reign of Christ. Unhinged from this grounding, the historical record is relatively clear that other gods (even secular ones) do not exercise such restraint. In other words, such an arrangement would be an implicit Christendom.
But what if we concluded that it was fitting to explicitly recognize the risen Lord as authoritative over our nation, and to do so even as representatives of public office? On the one hand, it would seem that this is as simple as saying that everyone’s (in all vocations) loving of their neighbor ought to be empowered by love toward and subject to the authority of the risen Lord. But doesn’t this stand in tension with freedom of thought or religion? In addressing this, it is important to recognize that this is not a question which is distinctive of those who contend for some version of Christendom. In fact, all regimes must ascertain the extent to which they adjudicate the exercise of speech in the public square and the ultimate authority which governs a nation. If recent political discourse has taught us anything, it is that the so-called “neutral” public square is often governed by implicit religion and attendant limitations on speech. But what of Christendom specifically? Of course, it needs to be recognized that there is a dubious historical record here. Much of what has gone by the name of “Christendom” has, in fact, violated many of the teachings of Christ and exercised its power in a way that does not reflect His teachings or His authority. Said differently, many have failed in the vocation of loving their neighbors through governance. The most prominent way in which this has been the case has been in the conflation of Christ’s reign with that of any historical commonwealth. In such a case, the distinction between vital faith and civic membership has tended to give way to coerced public faith and ignored private sin. A Protestant doctrine of God’s “two kingdoms,” however, helps us to imagine a Christendom which can, and in fact did (in concrete history), ground and guide the development of freedom, such as freedom of religion and the freedom of speech. Precisely because union with Christ by faith is not possibly manipulated and controlled by political power, the latter has limits. Civil order is penultimate and has very specific ends. There is still the obligation of all civic order to honor the risen Christ, but this honor can only ultimate be achieved through the very persuasion which Paul attempts in the book of Acts (in which contexts He asserts the authority of Christ). That is to say, it is precisely because Christ exercises His authority truly and wisely that He will reign in the hearts of men through persuasion and vital faith. It is no accident, therefore, that a healthy public sphere (adjudicated by persuasion and allowing for extremely divergent opinion) developed in Protestant countries. The reign of Christ limits the reign of any commonwealth, and in accordance with that limitation, any “established” religion (which is not to say an established institutional church) must emerge organically from below rather than as an imposition from above.
But surely an established religion implies the imposition of all the Bible’s rules in a modern society? Not so. In fact, the content of a Protestant version of Christendom need not necessarily be different from the content of any society governed by simple natural law – as clarified in Scripture by the principle of “genuine equity” rather than as a deposit of eternally binding positive law. And as such, any concern about Protestant Christendom would only reflect concern with natural law jurisprudence more generally.
However, the concern actually ought to be in the other direction. If political authorities recognized that the Lord Jesus could only reign in the hearts of men by means of persuasion, and if they recognized that His kingdom was greater than that of any commonwealth, would they not recognize their own limitations – the transience of any political order (helping to prevent state idolatry and its consequences)? Would they not recognize that, precisely because Christ loves their neighbor and commands all persons to follow Him, they must defend the orphan and widow, and allow men to come to form their opinions honestly and with conviction?
One could be pardoned for being a bit suspicious of the notion of “Christendom.” Its historical pedigree leaves much to be desired – though also much to be admired (and which has shaped many of those elements of our civilization which we most value). Nevertheless, clarified in the direction of Protestant principles, and recognizing that its alternative is only its parody (with a far more unsavory pedigree), it can be seen that Christendom is both as much as aspiration as a foundation. And as an aspiration, it is a movement toward the very freedoms that Western civilization has most valued. Nevertheless, this is secondary. Coming full circle, the chief orienting point is the simple fact that Christ is the Lord of this world.