R' Luria's acronym is the AR"I. The Hebrew of that roughly translates to Godly Rabbi Isaac. Why is he called Godly, and many other great rabbis are not?
I'm not sure the word means 'Godly' in the sense you are taking it. You seem to be taking in in the sense of 'the one similar to God,' while I think it might be meant to be taken as 'the God expert,' which would explain why the term is exclusively applied to him.