To practising Christians, and I would suspect Jews and Muslims also, religion is essentially a communal activity. If you look at the teachings and activity of Jesus it is clear that he is not simply drawing people into a private experience of God, but he is encouraging his small band to be community, and is vitally concerned with people's day to day lives.
I, for one, can't see the point of struggling with all this religious stuff if it doesn't actually have some effect on how life is lived. One has only to look at hundreds, nay thousands and probably millions, of socially active people throughout the world's history and see that many, perhaps most, of them are driven not be political ambition or intellectual commitment but by deep faith.
Outstanding examples are civil rights' campaigner Martin Luther-King, scientist - Isaac Newton, anti-slavery campaigner William Wilberforce, pioneer health professional Florence Nightingale, liberation campaigner Mahatma Gandhi and too many others to list, to realise that faith drives the political action of many, many people.
It is also noteworthy that as we look at even those few named above, they were not without their antagonists. No doubt many saying they should keep their religions out of politics.
I want to say that it is actually an affront to my personal liberty, is it not, to tell me that I can only practise my public religion privately.
Politicians may find it inconvenient when religious folk speak out about difficult subjects. But that doesn't mean they should deny people the right to do it.
Rather the reverse. In a democracy we should be encouraging, rather than discouraging people to engage with community debate.
A famous Anglican Divine, Lancelot Andrewes, wrote a treatise called Preces Privatae (Private Prayers). Here is one short section of those for whom he thought the Chriostian should pray:
Infants, children, youths, young men, grown men, old men, them that are in extreme age, the hungry, thirsty, naked, sick, prisoners, strangers, those without friends; the sick in soul, or body, weakhearted, those that are past hope; those in prison and bonds, those condemned to death; orphans, widows, strangers, those that travel by land, by water; those with child, those nursing children, those in solitude.
Plenty of political meat there I would have though
It is not difficult to see that Andrewe's, at least, appeared to think that the worlds of politcis and faith should be concerned about the same sorts of issues