There is a vast and unbridgeable chasm between America’s civil religion and Christianity. If we claim that “under God” refers only to the Christian conception of God we are either being unduly intolerant or - more likely - simply kidding ourselves. Do we truly think that the Hindu, Wiccan, or Buddhist is claiming to be “under” the same deity as we are? We can’t claim, as Paul did on Mars Hill, that the “unknown god” they are worshiping is the God of Abraham, Isaac, and Jacob. The Pledge is, after all, a secular document and the “under god” is referring to the “Divinity” of our country’s civil religion. Just as the pagan religion of the Roman Empire was able to incorporate other gods and give them familiar names, the civil religion provides an umbrella for all beliefs to submit under one nondescript, fill-in-the-blank term.
Al Mohler offers similar thoughts in his commentary, Is the Pledge of Allegiance Unconstitutional?:
Our God is a jealous God and is unlikely to look favorably upon idolatry even when it is put to good service. While we should be as tolerant of “civil religion” as we are of other beliefs, we can’t justify submitting to it ourselves. That is not to say that we can’t say the Pledge and think of the one true God. But we should keep in mind that this fight isn’t our fight and the “god” of America’s civil religion is not the God who died on the Cross.
Christians should be careful to think clearly about the Pledge of Allegiance and the current controversy. Secularists like Michael Newdow represent the hard edge of ideological attacks upon all expressions of theistic belief in the public arena. The truth is that the courts have allowed and driven a constriction of religious liberty such that any public reference or acknowledgment of the beliefs common to vast millions of Americans is now considered to represent an unconstitutional establishment of religion by the government.
All this puts believing Christians in a difficult position. After all, the Court has ruled that symbols and references to a divine being are allowable only insofar as those references point to no specific deity. Beyond this, the courts have ruled that the only permissible reference to deity is a reference that so reduces the definition of deity that it appears difficult for all but the most ardent atheist to object.
Because of this, Christians must not defend the presence of the word "under God" in the Pledge as a direct reference to the God of Abraham, Isaac, and Jacob--the Triune God whom Christians worship as Father, Son, and Holy Spirit. At best, the presence of this language in the Pledge and similar expressions on the nation's currency represent an acknowledgement of a power higher than the State itself and the nation's dependency upon that power for its safety and well being. Nevertheless, a decision from the Supreme Court that would require the removal of "under God" in the Pledge of Allegiance would represent a disastrous imposition of official secularism as the nation's public commitment.It does seem that we're between a rock and a hard place -- civil religion that tips its hat to a vague, non-descript deity on one hand and state-sanctioned secularism on the other. No follower of Christ finds the latter appealing but we have to watch against siding with the former because of its perceived utility in advancing (or at least sustaining) politically and socially conservative goals. In his excellent book Political Visions and Illusions, David Koyzis identifies two principal reasons why conservatives are likely to profess Christianity. The first is that they genuinely believe that its teachings are true. The second is because of the large part Christianity has played in Western cultural heritage. "For those conservatives who are Christians for this reason," he writes, "the issue of the truth of the faith is secondary to the social utility of its ethical teachings."
Some friends and I are reading John Piper's Pierced by the Word. We were all stopped in our tracks by this sentence: "God will not be used as currency for the purchase of idols." Civil religion, while it may use the word "God," sacrifices biblical truth on the altar of a political ideology.