The problem with atheists is that while they reject the concept of God, they don't analyze it.

Logically a spiritual absolute would be the essence of sentience, from which we rise, not an ideal of wisdom and judgement, from which we fell. The fact we are aware, than the details of which we are aware.

While secular culture has moved away from belief in god, it still resides very much in its shadow, of assuming ideals as absolutes and resorting to monocultural ideologies as substitutesConsider that democracy and republicanism originated in pantheistic cultures, which were the pre-modern version of multiculturalism. As there was no division between culture and civics.

So when we went back to these more broad based political systems, while retaining a monotheistic belief system, it required a separation of church and state, culture and civics. One of the problems Europe is having incorporating Muslims is that Islam does not distinguish between the two. Mullahs are the judges. Sharia law transcends national laws.

Given nature is a bottom up process, with this sense of being bubbling up through life, it would be logical to actually analyze it on those terms.

For instance, good and bad are not some cosmic conflict between the forces of righteousness and evil, but the basic biological binary of beneficial and detrimental. Trying to make sense of ethics, without taking this into account is like trying to make sense of a computer program, without understanding binary logic.

All the higher order, evolved social contructs, such as respect, responsibility, honor, trust, love, etc, as well as the negatives, are complex and many layered feedback of these foundational impulses. So when good is viewed as aspirational, rather than elemental, conflicts do quickly become a race to the bottom, of us versus them, good versus bad. Rather than each side being able to assume the other would hold to the higher standards and potentially evolve further.