Do you agree with this statement, "Christianity is America's official religion"?

Recently in my World Geography class, my teacher brought up this sentiment(he is a baptist and has very strong views) and we debated on this point, mainly because I questioned the validity of it. I don’t consider myself a christian, even though I celebrate christmas and easter, yet I firmly believe in God and that we should be and strive to be like he wants us to be. However I don’t agree with my teacher’s view on this. It may be prominent here, but I believe America is and should stay diverse. In the constitution it even says that we have the freedom of religion and also the separation of church state makes it where the government or state cannot be one religion over another or any religion at all for that matter. So what do you all think about this?