First of all, this command not to drink blood was written to Gentile Christians, not Jewish Christians. Second, it was addressed only to the Churches of Antioch, Syria and Cilicia. It says all of this right in the first line of the letter.
Then it seemed good to the apostles and the elders, with the whole church, to choose men from among them and send them to Antioch with Paul and Barnabas. They sent Judas called Barsab’bas, and Silas, leading men among the brethren, with the following letter: "The brethren, both the apostles and the elders, to the brethren who are of the Gentiles in Antioch and Syria and Cili’cia, greeting. (Acts 15:22-23)
The letter was not addressed to the universal Church. The letter was sent to Gentiles in Antioch, Syria and Cilicia. It was not sent anywhere else.
The four commands in the letter; 1) abstain from what has been sacrificed to idols, 2) abstain from blood, 3) abstain from meat that was strangled and, 4) abstain from immorality - these were the exact four requirements which Gentiles had to observe in order to be able to live in Israel amongst the Jews from way back in Leviticus 17 and 18. This delighted the Jewish Christians because it meant that the Gentiles could live among the Jews. It delighted the Gentile Christians because they didn’t have to be circumcised. Therein lies the genius of Jame’s solution - he extends this Law of Moses to this particular group of people at this particular time and makes everyone happy. This is a temporary fix for a particular situation in the Church in one specific area.
And these commands were not a matter of salvation apart from anything else that was not already taught such as the 6th commandment, avoiding sexual immorality, and the other commandments of Christ.
***If you keep yourselves from these, you will do well. Farewell. *(Acts 15:29)
The council did not say that they would not go to heaven if they did these things but only that they would “do well” if they observed these disciplines.
As to blood, we can drink Christ’s blood because God wants us to live the life of Christ. God said that the life of every creature is in the blood.
Only be sure that you do not eat the blood; for the blood is the life, and you shall not eat the life with the flesh. (Deuteronomy 12:23)
Ancient people drank the blood of animals and they lived like animals. We drink the blood of Christ so that we can live the life of Christ. God was telling people not to drink animal blood as a way to teach them not to live like animals. God was reserving the consumption of blood for when Christ came, so that all could drink the blood of Christ and participate in the divine life of Christ.
The blood is the life. We drink the correct blood, the Blood of Christ, not the blood of animals. We are to live like Christ, not like animals. This understanding of the Eucharist in light of Jewish law about drinking blood is how the early Jewish Christians understood so quickly that the cup was the literal blood of Jesus.
-Tim-