@ Paul from Cleveland
This is how I understand the issue. And I'm pulling quotes from jwfacts.com as I feel their research is very comprehensive:
The consumption of blood cells is not an issue in the Bible, as meat could be eaten despite containing blood. The issue was respect for the sanctity of life. Though Biblical laws on blood changed over time, showing respect for life never has. Is refusing blood in a life or death situation showing such respect? It is interesting to examine the scriptural development.
Genesis 9:4 "Only flesh with its soul - its blood - YOU must not eat."
This command is about respect for animal life during the ritual of slaughter. This does not state that blood could not be eaten. In its strict Hebrew wording, it means that an animal should not have flesh torn off it for food, whilst the animal is still alive. In general, it is understood to mean that out of respect for the life of an animal, it was to be bled when being killed for food; a command against eating things strangled.
The Watchtower uses this as a key scripture to show that blood transfusions must not be used, attempting to apply it to the consumption of blood - human blood. Neither point is made in this scripture. Even the Watchtower originally recognised that Genesis 9:4 did not apply to eating blood, as shown in the following article that attempted to prove that vaccinations were wrong.
"All reasonable minds must conclude that it was not the eating of the blood that God objected to, but it was bringing the blood of the beast in contact with the blood of man." Golden Age 1931 February 4 p.294
There is one occasion that on the surface may appear to complicate the issue on blood, and is the key scripture used by the Watchtower Society to justify its stance. At Acts 15:21 it is recorded that the Apostles and Older Men gave a decree to "abstain from blood". At first glance this may be taken to imply that the Mosaic Law was to continue applying to Christians in regard to consumption of blood. This is how Jehovah's Witnesses currently understand this scripture and is their predominate support for refusing blood transfusions.
Acts 15:21 does not apply to blood transfusions when understood in its historical and religious setting. It is not understood by the majority of Christian religions to be a binding command, nor was it understood as such by Pastor Russell. As already shown, the Noahide law on blood did not forbid eating blood, but was about showing respect when killing an animal. Blood transfusions do not involve taking life.
@Paul
So the way I understand it, is when this law was made it had a direct correlation to the taking of a life, and showing respect for that life taken. It wasn't the eating that was wrong, it was the disrespect shown for a DEAD animal. As the JWFacts website stated, blood transfusions do not involve the taking of a life. Therefore, the scripture does not apply to transfusions. You have to look at why the law was made, not just what it said. It had absolutely nothing to do with the physical digesting of the blood. Simply the respect shown for a dead animal.
Of course, this is only if you believe the bible is god's word. And again, just the way I understand it. Wouldn't be an issue if everyone thought the same way.
Aeiouy
Quotes taken from www.jwfacts.com