A present-day translation is not enhanced by forms that in the time of the King James Version were used in everyday speech, whether referring to God or man. For this reason, the are correct in avoiding these archaic pronouns. Again, purely grammar. So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of my mouth. This is not always the case though, as indicated with the Nicodemus example given above.
Thy banana is yellow.
As Subject Not as Subject 1st sing. My banana is here. The banana here is mine . The banana here is thine. As Subject Not as Subject 1st sing.