The question of a "higher power" have been tackled in different ways in the different series/movies. Too me the whole notion seems redundant in a Star Trek universe with species like Q,"wormhole aliens", Okampans, etc.
These are some of the questions i ask myself:
-A problem with the English language? Phrases like"Oh, my god" are hard to avoid.
I don't think that's really a problem. At this point, those sort of phrases are just common figures of speech, often devoid of meaning, and are hardly evidence of sincere religious belief.
If I stub my toe and exclaim "God damn it!" I'm not literally calling upon a higher power to condemn an inanimate object to eternal perdition. Ditto for "Oh my God!" or "Oh, for God's sake!" or even "Jesus f-ing Christ!"
If we accept that characters in Star Trek
routinely speak 20th-century colloquial English, as they have for decades, the occasional "Dear Lord!" or "Damnit, Jim!" are just par for the course and don't actually prove anything about the status of religion in the 23rd Century.
Hell, I'm a lifelong atheist and I just said "hell."