It is not uncommon these days for some people to regard religion as an unwanted guest when people start discussing social ills and their resolution. They regard the role of religion when it advances a moral position in the public square as poisonous because it is often suspected of seeking to impose that position on everyone else without their consent. Unfortunately some religious bodies have earned this suspicion because of their attempts to control the public dimension through an enforced and reactionary moral code. Wars have been fought over religious ideology (even though there were usually more basic political and economic issues at stake which used religious symbolism to mask their real interests). But we have to get beyond the 'religion or secularism' dichotomy regarding moral values and to do so some basic points need to be made.
First, morality is part of every human life and society. No one would claim to live an entirely a-moral life or live in a society without some commonly accepted moral principles guiding its social policies. But morality does not belong solely to people with religious motivations. The power of the ethical is part of every human life. And it can arise from a variety of diverse sources, from religious to secular.
Second, religious conviction, the source of moral values for religious people, takes a variety of forms, even within the same religious tradition. Progressive and fundamentalist Christians, for example, would claim a common religious tradition but reach quite different moral positions on issues such as homosexuality, the limits of the free market, the rights of women, health care, and pacifism vs. just war. And of course there are multiple religious traditions, from those accepting Abrahamic monotheism, to, among others, Buddhist, Hindu, Sikh, Jain, Baha'i, Unitarian, Confucian, Native American, and Wiccan forms of religion. There are also multiple shades of secularism, from the aggressively atheistic to the milder forms of agnosticism. So to rail against religiously grounded morality is like railing against the weather. It doesn't specify the issues at stake. Weather is too general a term and does not help us to know what particular climatological conditions we are concerned with. Religions and religiously inspired morality came in a variety of forms and expressions. And third, the religious voice has as much right to speak in the democratic public square as any other voice. As the First Amendment reminds us, in addition to no establishment of religion, no restrictions (save for the public safety) shall be placed in the way of the free exercise of religious convictions.
So where does this leave us? Back in the public square where each individual and group gets a chance to articulate its moral vision regarding issues of public concern. There are many issues, of course, that are of concern only within religious communities: e.g., the right of women to be ordained, the obligation to be baptized before gaining a vote in a congregation's affairs, who has the right to read the Torah scroll, and so forth. There are other issues that are central to the development of public policy, such as the civil rights of women and gay persons to be treated equally under the laws of the nation, the justice of which are also of concern to religious communities. Most religions have an interest in issues of justice and the social welfare of the nations in which they find a home. And as participants in the political affairs of those nations their members have a right to speak for what they regard as the moral dimension of public policy. They have no more but no less a right to try to persuade people of different convictions that their prescription for public policy is the best available for advancing the common social good. And the means of persuasion are those available to all members of the polity: namely, politics, persuasion, and the passage of laws that have secure sufficient support in legislatures. If you don't like the ethical positions of a religious group, provide an alternative moral position. You can't beat a particular moral value with an a-moral value since values are inherently moral. If you don't like the moral values of a particular religious group, challenge them with some of your own.
The first step toward a healthy robust democracy is to identify those public issues whose resolution will positively affect the common good. The second step is to marshal all the resources necessary to advance that resolution. Among those resources will be the moral voices of religious as well as non-religious individuals and communities. Often some religious voices will have more in common with secular voices than they will with other voices within their own religious tradition. But that is as it should be: a multitude of voices from a variety of moral convictions, coalescing around a common moral conviction that seeks to shape the best possible policies for the common weal. Let moral values compete for the allegiance of the electorate and may the most persuasive value win.