James Bannerman discusses the relationship between the church and the state, arguing that if they are not cooperating with each other, even if the state attempts neutrality toward religion, the result would be harmful for both institutions. A powerful example he uses is marriage. Note how profound is his case, though writing in 1868. His insight may be helpful for the church’s thinking about either the redefining of marriage stateside or the efforts to legalize no-fault divorce in the Philippines.
III. In the third place, I would refer to the law of marriage as another of those cases which illustrate the general position, that the civil and religious elements are so connected together in human society, that where they do not meet and unite in friendship and mutual co-operation, they must inevitably tend to the serious or fatal injury of one or the other.
Marriage is one of those institutions which, although not of grace but of nature, is yet adopted into the system of Christianity, and regulated by the rules which Christianity has laid down. The law of marriage has its origin in nature, and not in revelation; and yet the duties and rights connected with it, together with their exact nature and limits, are matters with which revelation deals. In so far as these involve moral or religious duties, we are to seek in the Bible for the code of law by which they are prescribed and determined. But marriage is, in another sense, a civil matter, coming under the province of the ordinary magistrate, and necessarily requiring to be dealt with in the way of civil enactment. There are civil rights intimately connected with it, in such a manner that the state cannot avoid the duty of legislating in regard to it, and regulating them by positive statutes and rules. In short, the institution of marriage is to be viewed in two lights,—either as a moral observance, falling to be regulated by the law of Scripture, or as a civil observance, falling to be regulated by the law of the state. And with this twofold character which it sustains, and this twofold legislation to which in every civilised and constituted society professing Christianity it is subjected, how, it may be asked, is a collision between the spiritual and the civil enactments on the subject—fraught, as it inevitably would be, with deadly consequence to the peace, if not the existence, of human society—to be avoided or prevented? If the state recognise the Bible as the Word of God, and the law of the Bible as the law of God, then it will take that law as the guiding principle for its own legislation, and make the enactments of the magistrate in regard to marriage coincident with the enactments of Scripture. But if the state do not recognise the Bible as the Word of God, there can be no security that its regulations shall not come into conflict with the regulations of Scripture as regards the institution of marriage, in such a manner as to put in peril not only the peace and purity of domestic life, but also through these the highest and holiest interests of human society. The ordinance of the family lies at the very foundation of civil society. It is the unit of combination around which the wider and more public relations of civil life associate themselves. Destroy or unhinge the domestic ordinances, unloose or unsettle the family bond, and no tie will be left holy enough or strong enough to bind up the broken and disjointed elements of human life. And yet, unless there be on the part of the state a distinct acknowledgment of the Word of God as the law to which its own laws must be conformed, there can be no security against the danger of the enactments of civil society on this vital point running counter to the appointment of God. The degrees of relationship or consanguinity within which marriage is valid or invalid,—the terms on which it is to be contracted or dissolved,—the rights which it confers on children, and the claims of succession,—all these are questions that fall to be determined both by the law of Scripture and the laws of the state, and any difference or conflict in regard to which must tend to unsettle the very foundation of human society. From the very nature and necessity of the case, if the state is not here at one with religion, it must be a difference deeply, if not fundamentally, injurious to the one or the other.
—James Bannerman, The Church of Christ (1868) loc. 2361-2393
Note especially that if the state does not align marriage law with the law of Scripture, there can be no security for marriage. Consequently, human life as we know it is in danger. Bannerman asserts, back in 1868, that the very foundation of human society will be destabilized. And that is exactly what we see happening before our eyes, today. The church has seen this coming, and yet it’s coming true.