But religious beliefs and practices also potentially support politics in many ways.
The extent and form of this support is as important to political philosophers as is the possibility for conflict.
In addition, there are liberal consequentialist concerns about establishment, such as the possibility that it will result in or increase the likelihood of religious repression and curtailment of liberty (Audi, 2000: 37-41).
While protections and advantages given to one faith may be accompanied by promises to refrain from persecuting adherents of rival faiths, the introduction of political power into religion moves the state closer to interferences which are clearly unjust, and it creates perverse incentives for religious groups to seek more political power in order to get the upper hand over their rivals.
Contemporary liberals typically appeal to the value of fairness.
It is claimed, for example, that the state should remain neutral among religions because it is unfair—especially for a democratic government that is supposed to represent all of the people composing its —to intentionally disadvantage (or unequally favor) any group of citizens in their pursuit of the good as they understand it, religious or otherwise (Rawls, 1971).
Similarly, liberals often argue that fairness precludes devoting tax revenues to religious groups because doing so amounts to forcing non-believers to subsidize religions that they reject.
A different approach for liberals is to appeal directly to the right to practice one’s religion, which is derivable from a more general right to freedom of conscience.
From the perspective of many religious people themselves, moreover, there are worries that a political role for their religion may well corrupt their faith community and its mission.
As European and American societies faced the growing plurality of religious beliefs, communities, and institutions in the early modern era, one of the paramount social problems was determining whether and to what extent they should be tolerated.