Never heard that it indicated the actual denomination of the family. Saints' names would imply R.C., possibly, and "Virtue" names (Patience, Chastity, Endeavour, etc) possibly Quaker, but I'd assumed that use of Old Testament names merely indicated Jewish or, more likely, Christian, (possibly non-Conformist?) rather than any particular sect or chapel, etc. It's an interesting thought - It'd be nice to know if there is any logic behind it.?