One possibility as to what defines a "god" is a creative function. Like for a Professor Moriarty, the crew members of the Enterprise along with its computer were collectively together the effective "god". Although the counter-crosswise power differential in the relevant episodes of TNG was an interesting exploration of the concept: even though Captain Picard and even more so Geordi Laforge could have shut down Moriarty "at any time", at least under normal conditions, the plot set up conditions that were highly abnormal to place Moriarty and the crew on more equal footing, even if only temporarily.

A more common refrain is that a "god" is something that is worshipped by some group of people - like a crocodile or hippopotamus could be considered a "god" to primitive proto-humans in that light. It is thus a device only useful as a quick explanatory function (don't mess with the god - it'll fuck you up with its huge powerful jaws or clawed feet!) until a society outgrows the need for such, and relentless curiosity demands a more precise understanding of what the large powerful being actually is.

But then after that, are there other "gods" - akin to whether there exists any magic as a source of wonderment - as one evolves further upwards? I guess we'll find out!! :-D