Mainstream Christianity counteracts the Jehovah’s Witness stance of refusing whole blood transfusions by biblical exegesis and also by examining the continuing changes in JW policy. Biblical Exegesis: In Acts 15: vss 20 & 21, that little word, 'for', shows the importance of context if we are to understand what went before it. I am not aware of any JW literature explaining why the reason to abstain from the list of activities (including abstaining from blood, in food and blood-guilt) has to do with the law of Moses being preached in the localities where Christianity was spreading.
Acts chapter 15 was about the problem Christians in the first century encountered in trying to prevent the Christian Jews from being offended and stumbled at the influx of Gentile converts. The dispute first arose in Antioch where some Christian Jews said, 'It is necessary to circumcise them, and charge them to observe the law of Moses' (Acts 15:5). This error was what the apostles were dealing with.
The law of Moses, including laws against eating blood and fat, had been fulfilled in Christ. Peter put the Christian view: "No then, why are you making a test of God by imposing upon the neck of the disciples a yolk that neither our forefathers nor we were capable of bearing? On the contrary, we trust to get saved through the undeserved kindness of the Lord Jesus in the same way as those people also" (vss 10-11). No amount of keeping the Mosaic law could save either Jew or Gentile (Rom. 7:6-7). Paul stated, "Christ by purchase released us from the curse of the Law by becoming a curse instead of us" (Gal. 3:13). Paul continued, "Consequently the Law has become our tutor leading to Christ, that we might be declared righteous due to faith. But now that the faith has arrived, we are no longer under a tutor. You are all, in fact, sons of God through your faith in Christ Jesus" (vss 24-26).
In the first century this was a huge change of understanding which many Jewish Christians had difficulty coming to terms with. Some, like those men in Antioch, had the idea that Christians still had to be circumcised and keep the Law covenant. That's why James gave the decision detailed in vss 20-21. The reason those requirements were laid upon the Gentile Christians was that from early generations Moses had in every city those who preached him, for he was read every sabbath in the synagogues.
This decree was designed to pour oil on troubled waters, to enable Jew and Gentile to come together in Christian fellowship. It showed that circumcision was not the important thing any longer. Almost immediately after this decree, Paul found himself in company with Timothy, whose mother was Jewish but whose father was Greek. Paul circumcised him "because of the Jews that were in those places, for one and all knew that his father was a Greek" (Acts 16:1-3) The very next verse says, "Now as they travelled on through the cities they would deliver to those there for observance the decrees that had been decided upon by the apostles and older men who were in Jerusalem". The very decision which stated that Gentile Christians were under no obligation to be circumcised! But if anyone was liable to stumble due to a Christian not being circumcised, then it was better that he be circumcised. The important point was that the newly circumcised Christian was not now bound to observe every detail of the Mosaic law. His circumcision was purely a gesture for the benefit of Jews with a weak conscience.
Similarly, the decree to abstain from blood was necessary to prevent Christian Jews from stumbling and to win over Jews to Christ. If any Jew saw a Christian eating blood he would be so repulsed that he would never even begin to consider the Christian faith. That's the connection of 'for'!
Knowing a brief history of the development of this blood doctrine is essential to see why Protestants cannot go along with it, as this is where theory turns into practice. The first President, C.T. Russell, wrote on the matter of what the Bible says regarding blood:
"These prohibitions had never come to the Gentiles, because they had
never been under the Law Covenant; but so deeply rooted were the
Jewish ideas on this subject that it was necessary to the peace of the
church that the Gentiles should observe this matter also." (The Watch
Tower 1909 April 15 pp. 116-117)
The Jehovah's Witnesses forbade blood transfusions from the late 1950s. It was from the early 1960s, after they brought in sanctions against members, that thousands of them started dying every year. It had become a doctrine by then, the claim being made that they must prove their loyalty to Jehovah and risk death rather than go against the interpretation their leaders had placed upon a handful of Bible verses. Here is evidence of the pressure brought on the JWs as shown in this 1961 edict:
"...the receiver of a blood transfusion must be cut off from God's
people by excommunication or disfellowshipping... if in the future he
persists in accepting blood transfusions or in donating blood toward
the carrying out of this medical practice upon others, he shows that
he has really not repented, but is deliberately opposed to God's
requirements. As a rebellious opposer and unfaithful example to fellow
members of the Christian congregation he must be cut off therefrom by
disfellowshipping."
But after the European Court of Human Rights intervened in March 1998, the Watchtower Society had to stop such sanctions, first against Bulgarian JWs, then for the rest. To appear to be seen not to be sanctioning members, they have stated in writing that no repentant JW is to be disfellowshipped for taking blood in the midst of a medical crisis. If they repent afterwards, they remain JWs. BUT if they do NOT repent, they are to be viewed as if they had disassociated themselves which, in practice, is the same as how they view those disfellowshipped - they are to be shunned. That is a sanction.
Clearly, the JW policy of refusing blood transfusions even at cost of one's life still holds good. The only change is that they cannot be seen to punish individual JWs who accept 'forbidden' blood treatments. They will give them the chance to repent, but if they remain glad that they are still alive thanks to blood treatment, they will be treated as if they had been disfellowshipped, and shunned. Protestants who know how JWs are affected by the blood doctrine realise that it's not enough to 'just' explain their biblical difference of interpretation on blood scriptures, because reasons for JWs going along with it include JW family and friends' reactions too. To counteract the JW stance on blood transfusions, it is just as necessary for Protestants to be sensitive to the emotional repercussions for JWs going against this doctrine.
Communique issued by the Secretary to the European Commission for Human Rights, Information Note No. 148 on the 276th Session, Strasbourg 2-13 March 1998, Application No. 28626/95
The Watchtower 15 January 1961 page 64