Matthew Cobb shared this entertaining infographic about when to use “tu” or “vous” in French:
I am tempted to make one for Romanian, which would be much more complex. When do you use tu, voi, dumneata, dumneavoastră, and maria ta?
I think the origin of this is that the modes of expressing formality by using the plural or a plural-based form of the second person pronoun are from later than, or other languages than, those in which the Biblical tradition was first expressed. But the result is interesting – one which makes people address God with less reverence than their boss.