Religion and politics are inexorably linked and we should respond to that through debate and democracy, not through attacking religion.
There are as many different reasons for entering politics as there are people who enter politics. Some see an injustice that they must correct. Some are personally affected by a policy and wish to change it. Some don’t care about policy as long as they have power or wealth. And some wish to shape the world as their religious beliefs tell them it should be, and that is not always a bad thing.
Politics and religion have always been intertwined and there are many political movements that emerged from religious roots. Of course there are as many religious viewpoints as there are non-religious, and so we see both Christian Socialism which has shaped the Labour party since the 1960s and at the same time we see the Conservative party full of Christians with right-wing policies. Religion is no guarantee of good or bad policies any more than atheism is but there is overlap between religious and non-religious policies and ideals so that religious roots may have no impact on whether a policy is considered good or bad by someone who is not religious.
I believe that religion and state should be separate. I think that when the state has an official religion, that religion is likely to be imposed on others by mandating prayers, services or ceremonies as part of government business and perhaps in other areas. We see lots of examples of this in the UK with prayers at the start of parliament sessions, and a religious oath before giving testimony in a court of law. (Although it is possible to opt out of this now.) I believe that in a multicultural multi-faith society this is wrong. Instead all government and all public services ought to be secular, without preventing anyone from following their religion. If politicians wish to pray about their duties I don’t have a problem with that, but like the councillor who recently won a court case to prevent prayer from being incorporated in the official agenda of council meetings, I believe that it should happen outside of the official government process. I believe that laws which impose a religious belief on us are a bad thing. I do not believe that government should impose any religious beliefs about who may marry who, or allow discrimination based on sexuality or any other attribute. I wish that religious politicians would not try to impose their morality on other people but instead stick to ensuring equality and justice for all.
For people who are raised in a religious environment there is unlikely to be any difference between their opinions formed through their upbringing and those that spring from their religion and so even if they wanted to, they could not separate the two. In any case, we cannot ask that people’s opinions are not shaped by their religion as to do so is to deny freedom of conscience, freedom of religion and freedom of expression which are all basic human rights. We must be allowed to think and believe freely. In a democracy people from any viewpoint should have the right to stand for election and to represent their voters if elected. Since we cannot prevent religion from shaping people’s opinions, the only way to oppose bad policies is to elect people of a different viewpoint and out-vote the policy. Of course in some cases this is impossible, such as in the case of Anglican bishops with a place in the House of Lords. I do not believe that bishops should have an automatic right to be in the House of Lords, but then it is not democratic anyway and the whole thing needs reform.
It is common to see people oppose a policy because the politician behind it is religious. I think this is disingenuous. Bad policy should be opposed because it is bad policy, not because of where it came from. If the only reason behind a policy is religion with no other factors then yes by all means oppose it on that basis, but if a Christian politician proposes a policy that you disagree with but has reasons other than their faith, attack the reasons and not their faith. To attack a policy merely because the politician behind it is religious is a bad argument and based on bigotry not reason.