I am T.A.-ing for a Social and Political Philosophy course which has exposed me to several issues in philosophy I have never thought much about. We are currently studying the modern philosophers Hobbes and Locke -- mostly on the relation of church and state.
Locke is clear in a division of church and state. The state promotes civil liberties (life, liberty, health, possessions, etc.) and the church promotes mutual edification and worship of God. He is also clear that force (taking away possessions, liberties, life) is an instrument only of the state. The instrument of the church is persuasion and reason. The church being a voluntary society, the worst it can do is to cast someone out of its membership.
In A Letter Concerning Toleration, Locke states, "If any man err from the right way, it is his own misfortune, no injury to thee; nor therefre art thou to punish him in the things of this Life, because thou supposest he will be miserable in that which is to come."
This made me think of the complaints people have of the 'religious right' attempting to 'legislate their morality'. Since this is a form of democracy things are a little bit complicated, but it seems that whatever law is legislated ought to be for the promotion of the civil liberties of the citizens. Religion cannot be compelled. We would not think that attending church should be legislated nor praying the sinners prayer nor taking communion. These are spritual activities that need to be undergone by choice, not force. If this is all right, then it seems that the only basis on can have for 'legislating one's morality' is that such standards promote the civil liberties of the citizens. I am not saying that this cannot be done, however, when you think of the arguments that are often advanced, the reasons put forward tend to have to do with such actions being immoral according to a certain (often spiritual) guidelines. If such things should be legislated against, it seems that they should be on the basis of civil liberties instead.