Religion's role in the public life of the United States has a complicated history, one that defies the easy generalizations that we see in popular media. While the federal government promised not to meddle in religion at the outset, the states were left free to do what each thought best. Some, such as Massachusetts, kept an established church (requiring those who did not worship at the designated church to jump through some hoops to be allowed to participate in the political process). They eliminated this centuries-old establishment only in the 1830s (more than four decades after separation was guaranteed at the federal level). Another approach--tried in the states of Pennsylvania and South Carolina--used fear of hell to keep voters and politicians honest.
This strategy limited political participation to men who believed in life after death and punishment for sin. As a religious test for politics went, this one was seen as minimal, allowing for broad political participation. The test invited into the political arena anyone holding traditional beliefs about punishment in the hereafter. Among the excluded were deists who thought of the Christian God as the creator but who rejected much traditional theology, as well as atheists. With this religious test, they intended to avoid examining the specific details of each individual's faith and practice (as was common in Europe) but to apply a broad standard that nominally kept religion in politics.
The logic behind the practice went like this: belief that sin would be punished in hell provided a check on bad behavior, which would help to keep the political process honest. The assumption, widely held, was that people who did not expect to be punished in the afterlife would do as they pleased in their present lives, to the determent of all. The idea was born out of a pessimistic view of human nature, one that assumed that people did right only if they thought they might get caught. Even as a few states passed this law, many Americans were turning toward a more optimistic view of human nature. According to the new view of human nature promulgated by the Enlightenment, people could be improved by education and by living in a well-run republic that permitted opportunity. Clinging to an older, more pessimistic view, these few states tried to use hell to motivate the populace to be virtuous.
The scheme failed. Determining who believed in hell proved tricky. Assuming the determination was based on self-reporting, then unbelievers might be expected to lie about it. But the idea had a deeper flaw: relying on divine punishment did not ultimately offer the hoped-for deterrent. Just as today, believers lied and cheated and stoled. Our own news streams are occasionally filled with stories of preachers caught in some conduct they have been decrying from their pulpits for decades. Relying on fear of God's punishment proved ineffective. The requirements for belief in hell were eventually cancelled.
Today many American voters want to know the religious affiliations--and to judge the religious sincerity of--candidates for public office. This informal prerequisite faintly echoes an older idea. In revolutionary America, it was an idea that few states endorsed and that those few eventually rejected. Yet it appears to have returned to our popular political discourse, or perhaps it never faded away fully. In any case some still take false comfort from the idea that if politicians are religious, their faith will make them better officeholders.