"It is not based on any religion or divine commandments, but upon "we the people"."
I guess you have never read any of the writings of the people who actually drafted the Constitution, or voted on it. Those writings are chock full of invocations of the Almighty, etc. Almost all were Christians. None were atheists; a tiny minority were deists. The only times atheists have been left alone to come up with a government system (as in the French and Russian Revolutions), they came up with dictatorship and mass murder. Why? Probably because they think most ordinary human beings are so so inferior to them that they couldn't be allowed to have choice, or even to live.
The Founders certainly had personal beliefs, but they were thoughtful about not imposing them on others.
Go, thou, and do likewise.
There is not a single mention in the Constitution about any god or about Christ. Art VI says atheists, pagans, etc. are equal because there "shall be no religious test."