Intuitively why atheism makes no sense in any cosmic model
Even if knowing the true structure of the earth is absent, the complexity and sychronicity of life alone is a no brainier for concluding there is a god (unless low IQ and brainwarshing is included).
In my opinion, I'm sure it is many others' too, the main reason why there are atheists is because they think they are an insignificant pale blue dot, a spec of dust, a fart in the wind. Knowing the structure of earth is essential, but besides that, all you need to do is look at the blueprint and raw materials that life runs off of. ask what are the chances of there being not only a water tight blueprint available, but also all of the necessary plethora of raw materials use to construct that complex blueprint DNA in a 3-d model (structural body), given nutrient rich soil and food with minimal environmental contamination.
Now if your an atheist and believe in the concave earth, I really don't know what to say. Although, being an atheist in a heliocentric model seems almost more mind boggling because how else could anything survive in such a chaotic and random environment, over time and distance scales completely beyond incomprehensible?
If there's no god in the helioC model how did the first spark of life happen? I don't remember who said this but, saying life came from a soup of chemicals is like saying every separate individual piece of a disassembled navy jet can be tossed into a hurricane and be put back together. Random things don't perform miracle after miracle over billions of years in a vast, fast game of cosmic bumper cars.
Re: Intuitively why atheism makes no sense in any cosmic model
This is coming from the point of view of an atheist who supports the heliocentric Earth model. I promise I won't try to convince you of atheism itself, but to try and help you understand it.
The main argument you seem to have is that everything seems to be too perfect for life, especially of this complexity, to be mere chance. I do somewhat agree with this, but there are some things you would need to know to put things into perspective:
Based on scientific observations, we can estimate that there are roughly a hundred billion (100,000,000,000) planets in the galaxy. There are also 2 trillion (2,000,000,000,000) galaxies in the observable universe, and the actual universe extends beyond that limit, possibly forever. This means that there are about 200,000,000,000,000,000,000,000 planets in the observable universe. If each planet represented drawing five cards from a deck of playing cards, then based off of probability you would draw a royal flush three times in a row hundreds of times.
These statistics provide many, many opportunities for live to start on any given planet. If you need to understand how things like gravity work over large distances, as you seemed to be skeptical of the stability of a heliocentric model, then I would suggest doing independent research on that, as I am nowhere near being a physicist.
You also seemed to think that life is so complex that it could never happen by accident. In reality, life started billions of years ago, and it was very, very simple, probably involving only a few chemicals and amino acids. From there, over the course of billions of years, life slowly went from that to being slightly more complex, eventually ending in the vast complexity of life that we have today. This, of course, is known as evolution.
As for the flat and concave Earth models, I think it would be impossible for an atheist to believe in either, because they both heavily rely on quotes from the Bible as evidence.