A personal moral code without God is achievable. A societally agreed upon one without God is much more difficult. People have very different backgrounds and interests, but if you are all Christian or whatever religion, you can generally agree on behavior. The ten commandments, golden rule, etc. The present has the benefit of generations who were raised with the rules, based on some religious code, but once further generations no longer have the ties to those texts and traditions, how do you intellectually justify the agreed upon societal codes based on those religions if people no longer practice? For example, virtues like turn the other cheek? It is not human nature. Why wouldn't you fight back if you don't have the authority figure telling you to do something against personal interest? And if the answer is NAP, who is the authority decides what is hurt? A religious code also unites across generations, gives many a sense of purpose, a cultural identity, creates a communal experience. If there is no God based moral code there is a power struggle for who gets to decide society's moral code because someone most assuredly will.
