I don't understand gods. When someone talks about advances in technology making humans as gods, or some fictional character believes that by doing some particular thing he or she will become godlike, I literally fail to see what the big deal is, and I'm convinced this is a terminology problem.
My beliefs are fairly straightforwardly monotheistic - I'm convinced that there is precisely one god. (Usually I'm going to capitalize this, as in God, not specifically for reverence - I can kind of see how "I consider God so important I'm willing to violate my otherwise-rigorous use of basic grammatical correctness for Him" makes sense, but considering how often "otherwise-rigorous" is a blatant falsehood I don't really buy it - but so that there's at least one visible difference between my use of the term and anyone else's.) More specifically, I believe in a God with the triple characteristics of omniscience, omnipotence, and omnibenevolence, which isn't really a word but I'm going to violate my otherwise-rigorous use of etymological yes I'm kind of being a hypocrite but it makes sense here, okay?
I think this means I use the same basic definition as the average atheistic person, and we just need to figure out whether such a God exists or not. That takes care of the first entry in Merriam-Webster. (I'm not sure what they mean by "supreme or ultimate reality" - it seems to imply that God is somehow more real than anything else, and I don't think I buy the concept of one person or object being more real than another one... is it possible to cite a dictionary for lacking rigor?)
Ignoring the mystical and arbitrary definitions, that leaves (2) - a being or object believed to have more than natural attributes and powers and to require human worship; specifically : one controlling a particular aspect or part of reality. This is the definition that seems to permit polytheism (and any forms of monotheism that don't believe in an omnipotent god), and my problem with it is that it's merely descriptive - not explanatory, and not compelling. My reasons for this are based on the key lines "more than natural attributes and powers", and "requires human worship":
What do we mean by natural? In the past powers that would have been considered unnatural would include things like, oh, sending a message to the other side of the ocean instantly, or throwing rocks into the air and not having them fall immediately back down. This is where Clarke's Third Law - "Any sufficiently advanced technology is indistinguishable from magic" - comes from. Taking that to its logical conclusion, if we're presented with some claimant to the title of a god we never have any good reason to believe any particular demonstration of powers is "more than natural"; sure, it looks like magic, but that's just because we don't know how to duplicate it. And since there's no real reason in theory that human understanding can't increase indefinitely (refer to the conclusion from my last post, that there's always more knowledge to know!), any power that's less than omnipotent can, and, probably, will be surpassed.
It doesn't make any more sense to worship Zeus than it does to worship your R&D department.
Now, there is a counterpoint to this, which is that it is right to pay more respect to more powerful people (which presumably means more respect for Zeus than for R&D, at least until the R&D chair is able to beat Zeus up). The problem with this is that it collapses into some form of might-makes-right (possibly bright-makes-right) scheme, which offers no grounds to argue with Zeus when he says to stop funneling so much of your budget into research and development, unless you resort to citing a higher authority than Zeus, and every possible higher authority can be answered this way... until you decide to cite an all-powerful, all-knowing, all-loving authority, who, funny thing, either exists or doesn't.
I have no issue in general with the existence of any sort of less-than-all-powerful being. But it's also entirely irrelevant to anything of more than temporary importance.