Most answers to that question seem to cherry pick quotes from the Founders - pious quotes to infer a "Yes" and Deist/unorthodox quotes to infer a "No."
I think that the Constitution was framed by leaders whose world view, values and common language were shaped by the Christian Bible - but who left ultimate questions of human destiny to the intersection of individual conviction and religion/philosophy rather than government.
So, if "Christian nation" means a government set up to propagate the Gospel of Christ - my answer would be "No."
But if you mean a nation built on Christian assumptions about reality - my answer would be "Yes."
Ah, how Anglican. A "Yes and No" answer. But here are some of the assumptions from which America might be described as a Christian nation:
- Recognition that humanity is not and cannot be perfect (depravity of man, original sin, fallen nature). Reading The Federalist Papers reveals the reasoning leading up to Constitutional "checks and balances" and other decentralizations of power. The Founders, without using the specifically Christian theological language, assumed a world in which people would inevitably seek to coerce and exploit one another. Majorities would bully minorities. Elitist factions would selfishly manipulate the majority. This is why statists and Utopians (and Utopian statists) tend to be non-, nominal or heterodox Christians. Once one rejects notions of inherent sin, one rejects a political system designed to frustrate the worst excesses of the fallen race.
- Affirmation of individual value apart from the collective. True, the Founders (being sinful humans, after all!) missed the mark when it came to the treatment of all kinds of souls who were not white male landowners. But their own values became the source of national critique and reform. Just as Jesus spoke the radical affirmation that, "The Sabbath was made for man, not man for the Sabbath" (Mark 2:27), America was founded upon the idea that government exists to protect the rights of the individual, rejecting traditional views of the individual as a resource for the honor of the state, race or tribe or even a national god and religion.
- Conviction that human value is God-given, not governmentally defined. The Bible frequently asserts the nobility of the "smallest" human being over/against the high and mighty of the world. Christ himself takes a wretched form while on trial before theocrats and bureaucrats. Some of our legal rights under Articles IV thru VIII of the Constitution rest on this foundation.
Certainly, these assumptions can be (and have been) divorced from Christian theological language - and the Constitution supports this by prohibiting "establishment of religion." Yet denial and ignorance of the Christian antecedents to our freedoms is a sure way to erode the liberty we enjoy. Willful ignorance of Christian foundations - especially the Founders' assumption that our rights derive from a transcendent source - assures the acceptance of secular myths designed to exploit individuals as fodder for "isms" and "ologies."