I had a 2-year dalliance with the Society of Friends AKA the Quakers back after college. They were big on thee and thou and that sort of nomenclature. They used it as a term of endearment.
The Quakers I hung with used it as sort of an inside joke. You used it in conversation with your family, close friends, and other members of the church. The old-timers might use it out in the open, but the younger folk kept it just among the other Quakers.
A Quaker mother might say "Thou must be quiet," to her child," when the normal mom might say "Be quiet!" or "STFU." It connoted intimate, motherly love and all that goes with it, without actually bringing out the strap. The message got through just fine.
There was a lot more subtlety to it than folks realized. I was happy for being among the Quakers and learning to use it. If you and a friend met a 3rd person and you wanted to introduce them, "Thou must meet my good friend, Fred." -- would indicate Fred was a brother.
I still use it around the house. KYHillChick will call me up and ask ,"What do you want for Dinner?"
I will respond, "What is thy will?"
Translated, "You know that whatever I want to bring home you won't eat, so why don't you tell me what it is I want, and we can get on with things?"
As I said, it's got a lot of subtlety
