[RPG] Forgotten Realms God of the Sea

In all my reading of Realms material over the years, I've never seen the “Roman” approach to other pantheons practiced or even referenced. Other pantheons are generally acknowledged as real, just foreign—a natural effect of living in a world where the individual gods regularly and undeniably manifest in person.

Instead, what you tend to see mentioned while reading Realms campaign materials are small shrines to individual gods or to pantheons as a whole. Where there are even a few worshippers of a god or pantheon, there will be a shrine somewhere where they can pay their devotions and tithe for its upkeep. Not all gods are represented publicly everywhere, since a public shrine to a hostile god would not last long facing the wrath of a local mob (and adventurers!); but such things tend to be either personal and private, or pop up in “underground” or black-market areas where they're overlooked—or better appreciated.

So if you're in human lands, you'll have to seek out some dwarven expatriates and find out where they worship their traditional gods. Failing that, you're on your own—you'll have to pray in this “wilderness” as best you can with your own devices, possibly constructing temporary, poor, personal shrines as you need to. After all, a paladin is a travelling sword of their god—it may be necessary to go to places forsaken or inaccessible to your god at times, as your god charges you to, and you can only do your best to honour them in such places.

Godhood is decided primarily based on power, which in turn is generally decided based on the number of worshipers the prospective deity has (paraphrased from DMG 5e, p 11 under Divine Rank).

That means that gods - both lesser and greater - grant spells to clerics as a defining trait. Not being able to grant spells to clerics makes immensely powerful beings quasi-dieties of some sort.