My point is that the Teacher said and I quote...

"Where do you get off telling a Muslim country that the United States does not consider itself a Christian country? Have you not read the Declaration of Independence or the Constitution of the United States ?

The First Amendment claims, "Freedom of Religion".

We have many religions in the United States, there is no "Official Religion" according to the 1st Amendment.

Religion in the United States

http://en.wikipedia.org/wiki/Religion_in_the_United_States

Religion in the United States is remarkable both in its high adherence as well as its rich diversity. Though the First Amendment to the country's Constitution explicitly forbids any official religion, the practice of religion and its importance in the lives of Americans are widespread and unusually strong among developed nations, with a majority of citizens reporting that religion played a "very important" role in their lives.[1] Because the First Amendment also guarantees free worship of religion, a large number of faiths, spanning the country's multicultural heritage, as well as those founded within the country, have lead the United States to become the most religiously diverse country in the world.[2]