From Dragon Eye Atlas
Unlike the other races, the dwarves do not worship gods. They acknowledge the existence of gods, but they firmly believe that a being so powerful does not need or appreciate groveling mortals.
Instead, dwarves venerate their own ancestors, their lives and accomplishments. Monuments to famous dwarves are everywhere in dwarven cities, and inscriptions praising the builders and founders can be found on dwarven homes, mines and other constructions. In ancient times, when the dwarven kingdoms were rich and powerful, the most important and admired dwarves got Ancient Dwarf Statues built.
In fact, the worship of ancestors is one of the reasons why dwarves are such stubborn traditionalists. "If it was good enough for my grandfather, it is good enough for me." is a common phrase to dismiss change.
Many humans and gnomes living in dwarven territories have over the years transitioned to the same ancestor worship.