Michael Gerson, former chief speechwriter for George W. Bush and now a columnist with the Washington Post, gives three reasons why “America is not a Christian country and has never been.”
“First, the Constitution was designed for religious diversity because the Founders were religiously diverse. The 18th century was a time not of quiet piety but of religious controversy. It was a high tide of American Unitarianism, a direct challenge to Christian orthodoxy. Thomas Jefferson's deism flirted with atheism -- a God so distant that He didn't even require his own existence. As journalist Jon Meacham points out, the Founders were less orthodox than the generation that preceded them, as well as the one that followed them. Their commitment to disestablishment, in some cases, accommodated their own heterodoxy.
Second, American religious communities were often strong supporters of disestablishment. Dissenting Protestants had a long history of resentment for the established English church. Others -- Catholics and Quakers -- were minorities suspicious of majority religious rule. Christians generally saw state intrusion as a threat to their theological integrity and worldly power as a diversion from their mission. They supported disestablishment for the sake of the church. And their political independence contributed to their religious vitality.
Third, as my co-author Pete Wehner and I argue in "City of Man: Religion and Politics in a New Era," America was not founded as a Christian nation precisely because America's Founders were informed by a Jewish and Christian understanding of human nature. Since humans are autonomous moral beings created in God's image, freedom of conscience is essential to their dignity. At least where the federal government was concerned, the Founders asserted that citizens should be subject to God and their conscience, not to the state.”