I beg to differ with George Blinick's comment that "the only group that has never waged war on another who disagreed with them religiously are atheists." Not true. I can think of an overwhelmingly Christian group of people who have never gone to war over religion -- the American people.
You might want to get a copy of Norman Cousins' "In God We Trust the Religious Beliefs and Ideas of the American Founding" and read some of the Founders' vision for America as a Christian nation. The states did not found a secular nation, they founded one that would have no national church, thus achieving religious neutrality toward all denominations and promoting religious freedom for everyone.
Meanwhile, here is Section 16 of the Virginia Declaration of Rights, which sums up the American Christian founding pretty well: "That religion, or the duty which we owe to our Creator, and the manner of discharging it, can be directed only by reason and conviction, not by force or violence; and therefore all men are equally entitled to the free exercise of religion, according to the dictates of conscience; and that it is the mutual duty of all to practice Christian forbearance, love, and charity toward each other."
Actually, atheists have been mankind's most murderous villains. Atheists like Josef Stalin committed war on his own people, resulting in the genocide of over 25 million Russian people. And Mau is estimated to have killed 65 million people in China who did not get on board with his ideas.
As John Stuart Mill put it in his book "On Liberty" (1859): "Atheism is false, and tends to the dissolution of society."