In the show we only really see the Starfleet perspective which is an organisation that doesn't need religion to function. Back on earth I expect there are plenty of traditionalists.
Whatever the truth about higher powers is, Religion is followed to serve needs. 5000 years ago people worshipped the gods who made the plants grow, because farming was such a crucial part of their existence. A failed crop one year would have caused widespread famine and death. We don't have that nowadays because we can source food from other parts, it just costs a little more to import.
Now maybe they were right, and there really are pagan gods, who are the only true gods. They must be feeling rather neglected nowadays.
When we feel confident and secure and adequately provided for by our own human effort, we feel less need for higher powers. It is only when we feel inadequate or frightened or unsure that we look to a relevant power for reassurance, and supportive influence.
Going by this, the 24th century seems to be a relatively clement and peaceful era, and I doubt that religion plays much of a role most of the time for most of the people. But when there were wars with extraterrestrials like the Klingons or the Romulans or the Borg, humanity may reform and reinterpret their religions as a reaction to those troubles. There may have been xenophobic tone in the sermons, talking about the horsemen of the apocalypse, or other evils coming from distant lands, or how those militaristic times were a call for jihad or equivalent.
It is easy to evoke the cultural interpretations when people feel needy. And like most traditions, religion offers a sense of belonging, and a sense of guidance.
