en_tn_lite_do_not_use/rom/10/16.md

not all of them obeyed

Here "they" refers to the Jews. "not all of the Jews obeyed"

Lord, who has believed our message?

Paul is using this question to emphasize that Isaiah prophesied in the Scriptures that many Jews would not believe in Jesus. You can translate this as a statement. Alternate translation: "Lord, so many of them do not believe our message" (See: rc://en/ta/man/translate/figs-rquestion)

our message

Here, "our" refers to God and Isaiah.