If God does not exist, what is the purpose of educating yourself? You will die, and if your works live on after your death, eventually nobody will be around to see those either. If you simply want to educate yourself for the benefit of yourself, what do you objectively gain by the endeavor?
My first response is because if god, as they don’t, do not exist, then all depends on us. We have no one else to wait on to give us this answers. That we must wrestle the knowledge from nature by diligently studying it, and coming back to it to arbitrate our claims. I would assume if a god existed, whichever god, and they were concerned about us and wanted us to have the right kind of belief, they would occasionally send notes.
My parents told me, to be competitive in the 21st century, I needed education and have a trade. Now that am old, I educate myself for the sake of knowing. I find immeasurable pleasure in learning something new. It opens my vistas. Expands my understanding of the world and so it is what I would call knowledge for its own sake.
I hate this questions of purpose. Must something have some preordained purpose to be enjoyed. It is silly to ask such a question. It is no different from asking why listen to music if god doesn’t exist.
I know I will die and will not be on the stage anymore. But while I live, I would love to be part of the conversation. It depends on what you write. Celsus, Cicero, Marcus Aurelius, Plutarch, Homer, Nietzsche among others wrote their volumes many eons ago. They have since died but we still read them. They have contributed to the improvement the human race, knowledge wise. And anyway, why should I worry about what will happen to my books, if I eventually get to write a few, when am dead, I shall be dead. Those who are lucky will find them useful in dismissing beliefs in superstition. They will learn, if they don’t already know, that it is important to be kind, not to discriminate and to treat each other with dignity.
Lastly, as I have said, what I again by educating myself is knowledge of the world around me, some of it practical and most of it, knowledge for the sake of knowledge. I could, for example, tell you that during the reign of Marcus Aurelius, Rome was governed by one of its best men. Here is an ideal to aspire to.
In conclusion, while we can disagree on whether a question is silly or not, this one assumes too much. The person asking assumes, that the god he believes in exists, that this god somehow is the reason they are educating themselves and maybe even after their death, this god may in someway be concerned with what they have left.