The gods of Formaroth don't hold much sway with the Blackwells, but they do not deny their existence. As 'low-born' individuals they had much more of the 'religion and hard work' ethic in their youths, but were conditioned by experience to put their 'faith', as it were, largely in merit and skill rather than the 'divine'.
For all intents and purposes, they are not religious folks, though at times Giles Blackwell, moreso than the others, refers to the concept of 'Death' as if an individual or a deified concept.
But as a whole they lack religious fervor and don't have any real belief in the divine.