Not sure if this would be better in the fanfic section but oh well.
Let me just say this first, I don't consider myself an Atheist so much as an irreligious person.

“Vesh’jir: How then, dear friend can you defend a doctrine of the Faith on some principle of logic when the exercise of the Faith requires an illogical action on the part of the Faithful?

Shak’kar: What illogical action do you refer to?

Vesh’jir: I refer to the practice of leaving a tithe of one’s harvest to rot all for the sake of appeasing purported Gods who may or may not exist. Surely that cannot be logical.

Shak’kar: But Jir my friend, of course it is logical.

Vesh’jir: If the Faithful were to instead keep the tithe for themselves would they not benefit more?

Shak’kar: Not at all. They require that tithe to be left for the Gods so as to ensure that they may have the crops next year to harvest and the health to enjoy those crops.

Vesh’jir: But what if the Gods do not exist?

Shak’kar: In that case it is still better to leave the tithe.

Vesh’jir: How so?

Shak’kar: In case the Gods do exist, then you’d be a fool not to leave a tithe for them.

Vesh’jir: Perhaps that is so and for not leaving a tithe I myself am doomed to suffer the Gods’ ire. But know that I have yet to grant the Gods their share for twelve years now and still here I am, healthy and strong with a bountiful harvest, a beautiful wife, and many happy, healthy children. And if it pleases you let us consider my bondsmen who do leave tithes for the Gods and do not have the means to feed their many children. So then I must give a tithe of my own but not to the Gods. I give a tithe to my bondsmen so that they may feed their families and provide future laborers for me. Which leads me back to my point: you say that it is logical to be wary of Gods and to follow their tenants even if their very existence is in doubt.

Shak’kar: Yes because if they do indeed exist then the person who doubted them would be sad indeed.

Vesh’jir: But consider that there are many different faiths which all have their followers and their doubters.

Shak’kar: Of course.

Vesh’jir: Do you not think that a man like you pious in your own faith would be no less loathsome to the Gods of another faith than I, a man who believes in no Gods?

Shak’kar: That goes without saying.

Vesh’jir: And consider that there are other worlds with other peoples and other faiths beyond the stars. The further you go beyond our own world the more and more different conflicting faiths you will find and the odds of your faith being the correct one become slimmer and slimmer. Yet here my belief that there are no Gods is not diminished as more faiths are included for the doubters are united in their doubt whereas the believers are divided in their beliefs.

Shak’kar: That is true, and a most troubling concept.

Vesh’jir: Then here you are appeasing one hypothetical pantheon while insulting an infinite number of other hypothetical pantheons. I insult all and appease none and yet here I am as wealthy and as good-fortuned as ever while your lands grow poorer and drier. You waste your time and your wealth when you make the futile effort of propitiating divine forces. Instead you could use that tithe to feed your family or you could sell it if you feel you have enough food to purchase the means to irrigate your land and ensure a better harvest next year. Do you not see? It is with our own hands that we take our fortune. You should instead use that tithe for something useful, something definite. In the end all that matters is that which we can see for ourselves. We can see the stars right now, shining on us and making the sky beautiful. These things are real and if I am right and there are no Gods then surely they are what we must aspire to.

Shak’kar: For someone who values practicality and utility so very much, you are quite visionary to suggest such a thing. What can we gain from reaching the stars if everything we need is down here?

Vesh’jir: Because dear friend, if we conquer the stars we shall be in the very celestial plane the Gods are believed to inhabit. Then if we find no Gods perhaps we can leave behind our superstitions and consider what our existence truly means.”

-From the Dialogue of the Viziers: 7950 (1316 CE)