That there were Judiasers in the early church, and this faction was calling for circumcision, and they were required new Gentile believers to be circumcised and follow the Old Covenant Mosaic laws. And these people who wanted to change the gospel were called PHARISEES.
"But some believers who belonged to the party of the Pharisees rose up and said, “It is necessary to circumcise them and to order them to keep the law of Moses.” Acts 15:5.
So, they had a great debate about it, in which only the apostles and elders were allowed talk.
They made a big decision about following the Mosaic Law, or the Old Covenant, which includes the important fact, that no one can keep the Mosaic law, and salvation comes through Jesus Christ.
"And after there had been much debate, Peter stood up and said to them, “Brothers, you know that in the early days God made a choice among you, that by my mouth the Gentiles should hear the word of the gospel and believe. [SUP]8 [/SUP]And God, who knows the heart, bore witness to them, by giving them the Holy Spirit just as he did to us, [SUP]9 [/SUP]and he made no distinction between us and them, having cleansed their hearts by faith. [SUP]10 [/SUP]Now, therefore, why are you putting God to the test by placing a yoke on the neck of the disciples that neither our fathers nor we have been able to bear?[SUP]11 [/SUP]But we believe that we will be saved through the grace of the Lord Jesus, just as they will.” Acts 15:7-11
So the law was a yoke which the Hebrews themselves could not keep, and it was putting God to the test.
The decision was that 4 things needed to be abided by:
"Therefore my judgment is that we should not trouble those of the Gentiles who turn to God, [SUP]20 [/SUP]but should write to them to abstain from the things polluted by idols, and from sexual immorality, and from what has been strangled, and from blood."
Acts 15:19-20.
Please note that probably only one is relevant to today. These were cultural norms, established to be a better witness to the world, and to prevent them from not really understanding that just because the pagan cultures were doing the 4 things, they should know it was better for the Gentile converts not to do this.
Again, the 4 things are:
1. abstain from the things polluted by idols,
2. abstain from sexual immorality
3. abstain from what has been strangled
4. abstain from blood.
All these things were done in pagan temple worship, including ritual cultic prostitution by both men and women.
The formal letter to the Gentile believers ends with:
"If you keep yourselves from these, you will do well. Farewell.” Acts 15:29
So basically, they instructed the new believers to NOT believe the Pharisees, and totally keep away from some pagan temple practices. And abstaining from blood is probably a health issue, besides being forbidden in ceremonial purity laws in Leviticus. And they were specifically told they did not have to obey the Torah and the Old Covenant laws, instructions and rituals.
Notice there was nothing about keeping a Saturday Sabbath, celebrating feast days, or keeping the law to keep their salvation.
The book of Galatians also deals with this matter, a very good read that ties directly into this chapter. I just am reading Acts, and was going to post on this subject, that even the Jerusalem Council did not require an adherence to the Mosaic or Old Covenant laws or instructions.
Really, If this is not a warning to Judasiers and the Hebrews Roots movement, I don't know what is.
As for Paul and Barnabas, that was a sad disagreement. Barnabas was the only one who supported Paul when he went to Jerusalem, and believed he had been saved. His ministry was encouragement, but after this "sharp disagreement" Paul took Silas on his missionary journey, and Barnabas took John Mark. We never hear about Barnabas again in the Bible.