Since the entire scriptural, historical, and medical basis for the ban on blood is baseless and incoherent, ultimately it rests on the credibility of the WT as God's organization.
Of course we can't rely on that either, because the history of the WT includes a ban on organ transplants and vaccinations. Today they allow those treatments, and therefore by their own admission they incorrectly placed restrictions on them in the past. Unquestionably people died adhering to those restrictions.
So if you ask a dub, "suppose it is ok to accept blood/organ transplant/vaccination in God's eyes. Is it then wrong for you to accept it even though the the org says it is not?" I am sure many of us have asked this question and received the following terrifying response:
"Even if the JW are wrong in their interpretation, they are God's organization. God would still expect me to follow His arrangement and obey His organization. We all die. But only those who submit to His arrangement can expect a hope of resurrection."
So my question from a scriptural standpoint is this:
Has God EVER given this sort of authority to men?
Has God EVER expected men to obey a human He chose as His special servant even when they acted outside His authority? when they acted in error? or against the conscience of the people His special servant is given authority over? to the point of sacrificing themselves or their children?