Anyway, I might dip my toes in this topic.
The reality is that we do have Morality, Ethics (and Justice, self-sacrifice, and many more) which become somewhat meaningless when we step outside humanity and look in from outside (so to speak). Yet, these things are critical to the survival of our culture(s)
Mankind either evolved along with religious ideas, OR, one of the many contradictory religions (or several of the non-contradictory!) may actually be true.
Personally, I am happy to pre-suppose the Creator God of traditional Christianity. But I have also put a lot of thought into how our religious ideas may have evolved.
Faith in God (it seems to me) is a very finely balanced thing. I can't not believe, I simply do. I can defend the logical correctness of Christianity, yet know that this depends on accepting the starting premises: That God IS, and that He has revealed himself in both Creation and His Word.
I also know, that if one starts with the premise that there is no God, then a consistent world-view can be constructed upon that premise also. Logically, anyone who starts with the premise, that there is no God(s), ends up logically proving that to themselves.
All human reasoning is ultimately circular - you cannot escape your starting premise. I have spent many hours in thought starting from either a believing or non-believing premise. (The very fact that I am prepared to do so upsets some of my believing friends.)
The problem is society itself - If evolution is true (let's assume so for sake of argument) then religion and ethics have evolved as essential parts of our society. To blow the secret, let the cat out of the bag & declare God is dead, amounts to a huge destructive influence on a complex evolved society.
There have been many attempts to replace religion with alternate ethical systems, but the "common" man refuses to catch on.
Fortunately, the small % still holding to conservative beliefs (in any system, not just Christianity) helps to preserve some social structure. The world malaise of unbelief is part of the cause of the rise of fundamentalism (which we see in Hinduism, Islam, Christianity and Judaism. Probably in eastern religions as well, but I am unfamiliar with those areas.)
Many view the destruction of any form of religion as a necessary part of the 'Revolution' and international socialism has always been opposed to genuine religious faith. Political systems also tend to mistrust those whose first allegiance is to another system.
Interestingly, within thinking conservative Christianity, (no, that ISN'T an oxymoron) there is an almost total opposition to AGW, while liberal-left Christianity is almost preaching AGW instead of the old-time Gospel. (They need something to believe in!)
(I have no idea what the Tele-evangelist/extreme fundamentalists believe - anything to keep the money flowing I guess)
No real conclusion - I know what I believe, and have a solid external ethical system to use with myself and my family.