He hath shewed thee, O man, what is good; and what doth the LORD require of thee, but to do justly, and to love mercy, and to walk humbly with thy God?
(Note: the words are archaic (and none the worse for that ); 'do justly' would today be something like 'behave in a just way'.)
I think the question mark in the end of the sentence works along with "but" - tell us that "nothing you can do except to do justly..." Am I on the right track?
I'm not entirely sure what your query is NHR, but the question mark is for the question: "…and what doth the Lord require of thee, but to… etc". More simply: "What does the Lord ask you to do?"
not a teacher