You asked for it, sports fans. Bear with me, I may wander. This is my second attempt, as I accidentally deleted my first. I suppose I should first address the question of whether or not the US was founded as a Christian nation. On the one hand, we have the First Amendment, stating that "Congress shall make no law regarding the establishment of religion or the free exercise thereof." On the other hand we have the fact that almost all of the Framers, and 51 of the 55 delegates to the Constitutional Convention were either Protestant or Catholic. (I'll get to the "establishment of religion" business later).
There have been assertions that the Founders were "Deists." Other than Thomas Paine, there is no evidence of any others subscribing to that belief. Washington and Jefferson were "anti-clerical Christians," meaning they contested the authority of the clergy. This was quite common in the time and place, largely as a reaction to the Catholic assertion of the infallibility of the Pope, and by proxy, his underlings. They were still Christians. I submit that the idea that anything other than some form of Christianity would ever dominate religion was so far fetched at the time that it was not seriously considered. The proscription in the First Amendment was placed there to prevent a "State Religion," such as the Church of England. Ironic, considering that 20 odd of the Convention delegates were members of that denomination. I hold the position that the US was founded as a Christian nation, based on Judeo Christian principles, because at the time, that was the only game in town.
Now, regarding AuntiE's request for elaboration on my statement that there is little Christianity in churches, I was referring to the pagan traditions that have wormed their way into the teachings of various denominations, and are being bruited about as Biblical in origin. (I'm starting to sound like one of those "rational theists" such as Thomas Jefferson now). Perhaps I should start with the Sabbath. Everyone knows it is on Sunday, right? The one taught in the Bible, and observed by Christ and the disciples was Saturday. There was no Sunday Sabbath until 321 A.D., when the Emperor Constantine, after one of the Nicene councils, decreed it so. This was partially a sop thrown to the worshippers of Mithra, which was a very popular religion among the Army. Mithra's sacred day of worship was Sunday. The "Catholic Encyclopedia" confirms this, along with the assertion, (found nowhere in the Bible) that the Pope having confirmed this, it is perfectly acceptable. Let us move on to Easter. Or should I say Eoster? Or would you prefer Ishtar, or Astarte? Easter has it's origins in Babylonia, in 2000 BC. The Sunrise service comes from there, celebrating the death and resurrection of Tammuz, who most definitely was not Jesus. Easter eggs and bunnies have their beginnings, as far as I can determine, somewhere in antiquity, predating even the Babylonians. The first mention of Easter bunnies that I have been able to find are in Germany in the 1400 to 1450 A.D. How the custom of making nests for rabbits to lay eggs in came about has eluded me this far.
The first mention of any celebration of Easter comes to us, once again, from the Emperor Constantine, in 325 A.D., as a curtain call, presumably, to his Sabbath decree.
Now for Christmas: Once again, we find the cult of Mithra involved, as Mithra, (who was, incidentally, born of a virgin on the 25th of December), The addition of the pine tree apparently occurred in Germany, about 800 A.D. or so. Irony once again, is that the only festival or observance that Christians were commanded to keep is that of Passover, which occurs around about the time of Easter. The irony derives from the fact that it's the only one that isn't kept.
There is more, but I'm skirting some of the main doctrinal points right now. If anyone is interested, I suppose I can pursue this further. My point is the politicizing of religion, and cherry picking this and that to make a religion fit a political belief. Obviously, this has been going on for a long, long time. The introduction of elements of various pagan religious practices to gain greater acceptance of Christianity for political purposes has been around for a while. Not only churches, but mosques are used to promote a mixture of faith and politics.
One last note: I can provide a bibliography for this, if anyone wishes, but you'll damn well pay me for it.

It wasn't you that concerned me. My commentary will reveal the true origins of some commonly accepted dogmas that have nothing to do with Christianity, but are foisted off on a low info congregation. Things like the origins of Christmas, Easter, Communion, the Sunday Sabbath, and other practices that have been added on over the years, that are found nowhere in the Bible, but are creations of Catholicism, Protestantism, and Orthodoxy, with an admixture of Greek and Scandinavian mythology, along with some Babylonian mysticism. In other words, window dressing and "isms " masquerading as Biblical teaching.