Religion in America influences the lives of individual believers, the conduct of family life, and activities throughout our civic life.
But it is the impact of religion on our politics that has attracted the most attention and evoked the most controversy in recent decades.
Since the election of Jimmy Carter to the presidency in 1976, evangelical Christians have dramatically increased their visibility and influence in American politics. Since the election of Ronald Reagan in 1980, they have tended to exercise their influence on behalf of the Republican Party and a conservative social agenda.
These developments have led many liberals to conclude that religion as such is hostile to their cause, and that America is too religious for its own good. While these beliefs are understandable, they are very shortsighted.
In the first place, religion in America is remarkably diverse, and it is a mistake to reduce it to the loudest voices in today's debates.
Mainstream Protestants disagree with their more conservative brethren on many matters. The Catholic Church often exerts its influence on behalf of working families and the downtrodden and against the use of force abroad. Jews offer a distinctive approach on many issues. The latest waves of immigration have brought new faith communities with new outlooks to our shores.
Second, religion in American public life is nothing new. The United States has been highly religious, right from the start. Sociologists often point to religious faith and observance as one of the central aspects of American "exceptionalism" — of what distinguishes our political culture from other advanced democracies.
From this standpoint, it is the decades prior to the 1970s, rather than the current period, that stand out as unusual.
In the late 19th and early 20th century, Protestants had been active in reform efforts ranging from settlement houses to the temperance movement. After the Scopes trial in the 1920s, many evangelicals and fundamentalists withdrew from public affairs and were content to be left alone.
This began to change in the 1960s after the Supreme Court decision outlawing prayer in public schools, and also in response to the startling cultural changes of the time.
The remobilization of Protestants into public life accelerated after Roe vs. Wade and efforts to remove tax exemptions for some religious schools.
By the end of the 1970s, the landscape began to resemble that of 50 years earlier. For Americans with no knowledge of our past, however, this situation appeared unprecedented and threatening.
The public impact of religion in our history is far more varied and profound than one would infer from today's controversies over abortion and gay marriage. A reasonable case can be made that without thousands of sermons delivered by Protestant ministers in the 1760s and early 1770s, the American Revolution would never have occurred.
Decades later, religious conviction stood at the heart of the abolitionist movement.
During the changes wrought by industrial capitalism and massive immigration in the late 19th century, Protestants proclaiming the Social Gospel spearheaded vital reforms.
After World War I, the work of visionary Catholics such as Father John Ryan helped lay the foundation for the New Deal. Without religious leadership and rank-and-file belief, the civil rights movement could not have succeeded and might not have existed.
Today, religious believers are at the forefront of efforts to fight famine, AIDS, and genocide in Africa. And there are indications that evangelicals are embracing a range of environmental concerns as well.
Yes, some believers go too far in using public power to impose their beliefs on others, but intolerance is hardly confined to faith communities.
Secular Americans should try harder to imagine how matters look to millions of their faithful fellow citizens. For example, why it appears to them that misguided public policy has unleashed a torrent of violence and vulgarity in our media.
While religion may partake of the divine, it is largely a human enterprise. As such, it reflects the complex human weave of good and evil. Still, sober observers believe that religion has reinforced what Abraham Lincoln called the "better angels of our nature."
Our first president concluded that "reason and experience both forbid us to expect that national morality can prevail in exclusion of religious principles." While religion is far from perfect, there is no reason to believe that America would be a better place if we were less religious.