(I am going to regret this - I am overstepping the bounds of my energy. Jem, I still owe you a reply in our earlier "Name of Jesus" discussion, but haven't found the energy yet - please don't expect me to get into a discussion about this.)
In 1986 I was diagnosed with stage IV non-Hodgkin lymphoma - a cancer of the white blood cells that had spread everywhere except to cerebrospinal fluid and to my bone marrow. Some 25 sessions of chemotherapy didn't manage to kill off the cancer cells, so eventually it was decided I was to have an autologous bone marrow transplant.
Bone marrow was harvested (by drilling 120 holes in my pelvis), and I was given a strong poison that would kill of all my blood cells (and a lot more - together with the chemotherapy this is also the reason for my chronic fatigue). Then my bone marrow stem cells were released in my "blood", from where they swam back to the bones and slowly started rebuilding my bone marrow, and producing blood cells.
During this time of regeneration, I had no blood cells of my own, and survived on regular doses of donated red blood cells - necessary to transport oxygen from my lungs to my organs.
Obviously, my own blood, being ineradicably infected with cancer, would not have done, so if I live on this side of the grave, it is fully thanks to those who had the generosity to give their blood. (As far as I myself was concerned, I would not have minded dying and being with Christ at all, but that is besides the matter here.)
At the time I had come to know God, but wasn't into the intricacies of Biblical life yet, and it never occurred to me that there might be a spiritual aspect to receiving blood.
In the OT, consuming blood was forbidden because the soul is in the blood (Leviticus 17:11). The soul is not in the flesh, so flesh can be consumed, but it is in the blood.
In Acts 15:20, the apostles don't want the Gentiles to deal with "what has been polluted by idols" - such as the meat in pagan meat markets. Yet, in 1 Corinthians 8:10 Paul acknowledges that with the right mindset one can even eat
in the idol shrine itself! - or one could, if it weren't for those brothers who were less mature. There is a fine, but very clear, line here between
eating (even during an idol sacrificial rite) and
partaking in that rite (1 Corinthians 10:19-21), and it is very understandable that for vacillating others the one might all too easily be taken for the other.
In the case of the apostolic letter the "weak ones" were the Jews, who had been hearing the Mosaic Law all their lives (Acts 15:1, 5, 21). Possibly the apostles were thinking of the Jews in general, for whom no stumbling block should be put - one of the first things Paul does is circumcising Timothy for the same reason, even though he preaches vehemently against circumcision elsewhere.
Another possibility is that the Jewish brethren were meant - those who had accepted Christ, but were still strongly attached to the Law (Acts 21:20). To them too we see the mature Christians accommodate (Acts 21:21-24).
In either case, the ruling is clearly given out of consideration for immature minds. Another rule however, sexual morality, is clearly a general and enduring one, one reinforced in all NT teaching (though it might have been included to cover some specific behaviour abhorrent to Jews yet acceptable under the Royal Law). So how is the blood rule to be interpreted?
In the OT, there is a double line of argument:
- The killing that comes with eating meat is evil (Leviticus 17:4). The souls of the killed cry out to God (Genesis 4:10; Revelation 6:10).
- God Himself promised His blood on the altar (Leviticus 17:11 - Acts 20:28) of which the animal blood was only a preshadowing (Hebrews 10:4).
Both lines come together of course in Christ's death - .
Neither line still holds: transfusion blood is not extracted against the will of the victim by killing him, but is taken from the giver without any serious harm to him. It is a freely given gift of life, a worthy imitation in the small of what Jesus did in the large, and the soul of the giver won't cry out against the receiver. And the atonement has been accomplished; no preshadowing is needed anymore (and Christ's blood speaks more powerfully than that of the souls crying out: Hebrews 12:24).
And indeed in the rest of the NT we don't see any injunction against eating blood (even though recipes with blood were exceedingly common in many parts of the ancient world).
We shouldn't eat blood if it hurts weaker brothers, that is obvious. But if it comes to saving lives, erring on the side of the Law can go directly against the Law of love, as Jesus illustrated with the example of the priest (Luke 10:31) who refused to check whether this traveller was really dead (Leviticus 21:1, 11). In such cases James 2:13 holds.