My two cents is that all of us are products of history and geography. History lies deep within us, even if we don't conciuosly realize it.
North America and Europe is the offspring of 2,000 years of culture which germinated in the ethical, cultural, and social traditions of the Abrahamistic faiths.
Naturally, it has been seasoned at the margins with a little eastern and south Asian thought, particularly as we incorporate more immigrants.
But, in this country, whether one is Christian or not, the vast majority of citizens have either directly or indirectly been influenced by the Judeo-Christian culture, ethics, and history this society has been stewing in for two thousand years. Even if only in the most oblique way.
I do not see us reverting to the values, ethics, or culture of Greco-Roman civilization, Aztec civilization, or archaic Celtic civilization.