Of course not. It doesn't say that anywhere, regardless of what you saw on the internet, or wherever.
I'm just encouraging you to say what you're thinking, because this pathology fascinates me.
The Preamble: "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights, that among these are Life, Liberty and the Pursuit of happiness.”
Clearly our founding was considered "Christian."
It's generic Christian, no one has seriously tried to force any specific denominations on the country. And you're going to have to point me to anyone denied anything here because they aren't "Christian"