Thanks Ghostavo.
It's important because a vocal minority and their elected officials are using the phrase "One Nation Under God" as if it's the founding principle of our country and are using it to jeer at and dismiss the opinions of non-Christians. This is increasingly being translated into policy, in contradiction with the guarantee of religious freedom granted to all citizens by the Constitution. It has very tangible effects on (for example) Veterans Affairs, science education in public schools, and freedom of individual expression.
As for your assertion that the US was founded by Christians... well, it's irrelevant since the United States wasn't founded on the personal convictions of the Founding Fathers, but on the consensus they reached when they wrote the Constitution. But try to find me a quote from Thomas Jefferson, James Madison, John Adams, or Thomas Paine that speaks of Christianity in a positive light. I'm not trying to be divisive or offensive, but I would like the record set straight.
And, er... EULAs are kinda important too (software usage rights, privacy policy, spyware/malware installation, etc.) If I were you I'd consider reading legal documents before signing them.