Greetings,
The prohibition against blood is derived from the Scriptures, NOT from some human source or even the Christian Congregation. It originates from God Himself, therefore the prohibition against blood use is a Scriptural fact and will never be changed for Christians.
God's Law for Christians is unequivocal: "Abstain from blood!" And "Keep from blood!" (Ac.15:20; 21:25). It required a complete unqualified "abstention from blood" since there was no stated verb such as "eat," "drink" or "touch." They must "keep away" from it (Ac.21:25). This Apostolic command placed avoiding blood as equal to avoiding fornication or idolatry! Just as a Christian would not commit fornication or idolatry to save his life, so too we should avoid blood (1Cor.6:9-11).
The use of blood in transfusions is obviously contrary to the specific command not to "eat" blood. Eating intravenously is still eating. This can be illustrated by a doctor telling a drunkard not to "drink" any more alcohol or he will die. Now, if the man were to hook himself up to an IV and directly infuse the alcohol to his veins, would he be obedient to the doctor's mandate? Regardless of the alcoholic's technical argument concerning the mechanics, he still would be arbitrarily sidestepping the doctor's order. Is there really any difference between this use of alcohol and that of blood? Putting blood into our veins is not "abstaining."
Also, we could well ask you the same type of question: Since EVERY other religion has changed its teachings so many times on major issues like warfare, being the only true religion, women in the pulpit, homosexuality, racial superiority, predestination, literal hellfire, Michael being the archangel, vaccinations, women having souls, and etc. how do you know they will not change their teachings on the Trinity or Christ's ransom?!!!
Every Witnesses knows that their beliefs have at times changed because of increased knowledge or changes in the way serums and vaccines were made. But of course even the Apostles had to change their beliefs regarding their understandings of end-times (Lk.19:11; 24:21; Ac.1:6). Criticisms regarding Witnesses changing their understandings on how to apply the Scriptures would also condemn the Apostles!
Obviously there is something wrong with such criticisms.
Having to correct misinterpretations is not proof that a religion is not God's organization, or that an individual is not a Christian. A failure to correct false doctrine or actions when presented with solid evidence would be!
BLOOD FRACTIONS
Now, when it comes to the use of blood fractions "The Watchtower Society" does not "approve" nor does it "disapprove" any use of fractions, it simply educates its members as to what these are and any dangers involved. It has ALWAYS been clear that each individual must decide for themselves whether to use fractions.
The reason most Witnesses accept "fractions" derived from blood is because when blood is fractionated it is literally destroyed and so the Scriptural law is fulfilled, i.e.; the blood had to be destroyed if it leaves the body.
Once blood is fractionated it is no longer blood nor will it ever be blood again. While you can separate the major components of blood and then put them back together to get blood, this cannot be done once it is fractioned. Nor is it even possible to use "every part of blood" with the current fractioning process.
While minor understandings of prophecy and periphery beliefs may continue to be adjusted and refined, major doctrines such as transfusions of blood will not be changed. This is because we are deep into the endtime and the doctrinal knowledge has increased tremendously so any recent changes have not been to *doctrine* but simple refinements in knowledge.
Below is a quote from the theologian Charles G.Finney from the introduction to "Systematic Theology":
"Finite minds, unless they are asleep or stultified by prejudice, must advance in knowledge. The discovery of new truth will modify old views and opinions, and there is perhaps no end to this process with finite minds in any world. True Christian consistency does not consist in...refusing to make any improvement lest we should be guilty of change, but it consists in holding our minds open to receive the rays of truth from every quarter and in changing our views and language and practice as often and as fast, as we can obtain further information....No Christian, therefore, and no theologian should be afraid to change his views, his language, or his practices in conformity with INCREASING LIGHT."
Yours,
BAR-ANERGES