They often excluded themselves because participation and membership in these organisations meant worshipping Caesar. All too often simple rituals, prayers, libations and other elements of the pagan cult were part of the warp and woof of daily life in these institutions. Christians could not in good conscience participate in even these seemingly harmless, even trite rituals. As a consequence they were decried as anti-social.
We must remember that exclusion isn't quite the same as overt persecution. For Christians this is the norm. It's just the expected and even necessary opposition of the world, the fruit of Biblical antithesis, and a reminder that we are but strangers and pilgrims on this earth. Exclusion is a type of small-scale persecution that we should both expect and embrace. And yet some forms of social polity can lessen the burden.
One of the blessings of modern secular culture is that many of these elements, these sacralised, religiously coloured rituals have been removed from many institutions and aspects of daily life. I know, you're not supposed to think that way. According to the leaders of Evangelicalism we're supposed to lament secularisation and the separation of Church and State. In fact the paradigm actually represents the New Testament ideal, a socially pluralistic society in which we can function as the Church and live in peace among our pagan neighbours.
It must be lamented that pluralism is being eliminated by both the Secularists and the Sacralists. Secularism like all social forces is necessarily dynamic and devolves into a type of Sacralism. That's the nature of fallen man. He makes idols and tries to build Babylon and he worships what he creates and what gives him power. Sociologically the tendency is to consolidate power and transform society into a social monism wherein everything takes on a religious meaning. The anti-Scriptural Judaizing Constantinian tradition embraces this within a Christian framework.
Secularism in the end is just as much a religion and dependent on 'faith' in the transcendent and unseen as any other religious system. Though true secularism is a myth, from the standpoint of Scripture, it can (if restrained) be a desirable social polity. Pluralism, even the liberalism of the classical tradition is desirable. It's not remotely Christian or even moral, but creates a helpful environment facilitating the peace of the Church. Like any social system it is inevitably unsustainable being subject to dynamism and perversion. But at present, instead of preserving this pluralist social order, both camps (the Secular and the Christian) are aggressively working to destroy it. The Founders of the American Experiment would be both baffled and dismayed by these factions that claim their legacy.
As Christians we live our lives as martyr-witnesses, living as strangers and pilgrims among the lost. Pluralism generates a degree of tolerance though even under such a system we will still be socially ostracised and ultimately disenfranchised. Such a situation is completely compatible with the Church's place in the world as envisioned by the New Testament. On a pragmatic level we can embrace the concept of social pluralism while at the same time reject any claims of moral relativism. We're not 'on board' with the project or its philosophical foundations, it's simply the best we can hope for in This Age while remaining faithful to New Testament ethics.
We vigorously reject theological pluralism, we don't accept the claims of its various cults nor grant them equality of fellowship or extend to them eschatological hope. They will find this offensive, but the social contract (when genuinely pluralistic) affords that we can still be neighbours continuing to live and work side by side.
Christian Sacralism seeks to destroy this arrangement and create a Pseudo-Kingdom on this earth, one in which the gospel is wed to the violence and vengeance of the state and the unbeliever is compelled to keep an outward form of Gospel obedience. This destroys the testimony of the Gospel, Christian ethics and in the end corrupts and destroys the Christian Church, leading it into apostasy.
Rome, Magisterial Protestantism and modern Evangelicalism have embraced this path. Even Secular Sacralism, the religion of Materialism falls into the same course. It has forged a religion with its own (anti)-metaphysical narrative, epistemology and ethic. The Sacralisms are at war, and we are (as it were) caught in the middle. Sometimes I don't know which is worse but one thing is clear... false Christianity is a greater threat to the Church than anti-Christianity. To the worldly-wise that's counterintuitive but it is nevertheless the case and it might be added, the viewpoint of the New Testament.
Christians were and are second-class citizens. That's our calling, our vocation as it were vis-á-vis the world. We seek to live at peace with the state, obey its laws, pay our taxes and be productive members of society. We are not at all hostile to the state. In fact we can be thankful for the relative peace of society which necessarily involves some form of authority. We do not buy into the Libertarian lie and its anti-Christian philosophies regarding the state nor its sub-Christian anthropology. Libertarianism has not only shifted politics in the United States, it has (like a cancer) worked its way into Christian theology and ethics. The resulting hermeneutics and exegesis are leading Evangelicals down some very bad (and even dangerous) theological and ethical paths.
Though we embrace the state as a temporary outworking of Providence, we don't use their courts and we don't call upon their forces of violence to help us in Kingdom tasks. We don't expect the police or armies to aid us in our holy endeavours and we don't help them either. They serve God's purpose in restraining evil but not for godly motives. Christians participating in these organisations have been deluded and their consciences have been compromised if not seared. Thinking they are ministers in an aspect of God's Kingdom, they have in fact signed up with the forces of Babylon and they need to extricate themselves and repent. Their 'ministry' as Paul describes it in Romans 13 is in the realm of Providence not the Covenant. In that sense Nero, Nebuchadnezzar, Tiglath-Pileser and Cyrus were all 'ministers'. This 'service' is not wed to the Kingdom. It is not a holy vocation. Providentially the state falls under God's Reign to be sure, but it is not part of His Holy Covenantal Realm.
Just because it's non-holy, it doesn't mean the office is necessarily un-holy, though it often becomes that. We're not against the state but we're not for it either. We pray for them, even for the peace of the city, but we don't bless their endeavours nor encourage them in their lies and trickery.
There is no ideal political order. All man-made polities are false, built on false foundations and doomed to fail. If living under a Capitalist system, we will have to bear witness against it. If we live under a Socialist system we will have to bear witness against it as well. This is true of Monarchy, any militarist construct and those that argue for no government but would in reality hand governance over to corporations, profiteers and/or mafia bosses and warlords.
We operate within the state's parameters as long as its policies don't cause us to sin. We don't have to try and hide from it, resist it or avoid supporting it with taxes. Both Christ, Paul and Peter affirmed that Christians were to pay taxes to Rome even as Rome used those monies for wicked deeds, evil policies, wars of conquest and pagan temples.
As residents and citizens we can claim tax credits. The social order seeks stability. We don't expect justice. Virtually every government devolves into criminality at some point. We need not evaluate the tax policies in light of justice or theoretical validity. If the government wants to tax one group over another, so be it. Stability and order are what we seek. In a modern society, streams of revenue and taxation are complicated. While we might have a 'progressive' tax when it comes to income, we don't when it comes to other forms of wealth. In many cases the tax system can actually be 'regressive' benefitting the wealthy. It should come as no great surprise. The entire system is rigged, criminal and exploitative. We're not going to fix it, nor are we called to. Content with our daily bread, we should expose their lies and we certainly shouldn't 'sign on' with the corrupt system and profit from it and its exploitation of others.