The doctrine of salvation by grace was at stake at the council of Jerusalem; which is why Paul and Barnabas fought so hard to preserve it.
If the opposite decision had been made, there would be no Christianity except as another sect of Judaism. Every believer in Jesus Christ would be required to wear tefilin, tzitzit, and tallit, and be circumcised, and keep every aspect of the law; and the doctrine would be that these things are necessary for salvation.
I've studied Judaism some. The controversy was unnecessary since informed Jews have always believed in the concept of the "righteous Gentile." They did then and still do. The laws of Moses were given to Israel not to Gentiles. Israel agreed to those laws when they took the vow at Sinai. My ancestors didn't. Why would I be bound by them then? If I converted to Judaism and got circumcised, then I would be obliged to keep the laws of Moses. That is what Jews believe if they're informed.
The Gentile however is bound by the Covenant of Noah. If he keeps those commandments, he's fine with God. If you look at what the Jews teach, you will find their list is very close to the list of the Apostles. I'll cite only the concluding paragraph here but provide a few links in case you're interested in reading more about what Jews teach and should teach. This is from:
The Noahide Laws | My Jewish Learning
Conclusion
That Jews perceive non-Jews as bound by a set of laws–even if they are not bound by the full range of Torah law–is a significant statement. The expectation that non-Jews will set up their own system of justice became the basis for peaceful interactions between Jews and non-Jews. The Noahide laws separated humanity after the flood from the lawless violence which brought God to the point of destroying the world. The Noahide laws stand as a testament to the Jewish belief in the need for the rule of law to protect all peoples.
Wikipedia also has a good article on it:
Seven Laws of Noah - Wikipedia
There are some things that all men know without any need to be taught; and those are necessary for salvation.
Romans 2:12 For as many as have sinned without law shall also perish without law: and as many as have sinned in the law shall be judged by the law;
13 (For not the hearers of the law are just before God, but the doers of the law shall be justified.
14 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:
15 Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another-
16 In the day when God shall judge the secrets of men by Jesus Christ according to my gospel.
God will judge people by "the law written their hearts."
For example, a Gentile may know he should put a fence around his swimming pool so people don't accidentally drown. He is obeying the Law of Moses in spirit because Moses was trying to teach people that when they build things, they need to love other people. Thus the commandment:
Deuteronomy 22:8 When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thine house, if any man fall from thence.
People then often slept on their rooftops at night. A wall was needed to protect life. Today we don't have flat roofs. Such walls would be pointless -- obeying the "letter of the law." The Sanhedrin was supposed to keep interpreting the law then, by the spirit of the law. That law would mean you need a fence around your pool.
There was a time when the Sanhedrin interpreted the phylactery rule with only a spiritual meaning, No one had to wear them. Then a later Sanhedrin thought using a physical one would help people do the spiritual one. Over time, some people thought wearing the physical one was what mattered; and Jesus mocked them. They were keeping the law in a material sense, by the letter so to speak, but forgetting its spiritual meaning.
So if you do the right thing without obeying the law of Moses "by the letter," you are actually keeping the true law which the "written" law was supposed to teach Israel. Sad to say, observing the laws by the letter wasn't working. The Sanhedrin invented "burdens" for the people, making unnecessary and hard rules on how the Law of Moses needed to be kept -- while ignoring the real intent.
The Jews who wanted all the Gentiles to observe all the laws of Moses were "unlearned" themselves. The right position is what informed Jews today still say and what the Apostles said.
The Sanhedrin was supposed to interpret the Law of Moses to fit the changing cultural context. My objection to several practices the Catholic Church set up was they were unnecessary burdens. They did not teach people about love. All they seemed to see was that they believed they had the right to say what practices should be -- forgetting that good practices should be based on the Law of Love. I also object mightily to their setting aside of the prohibition of the eating of blood -- that is part of the Noahic Covenant which everyone should know to obey.
The Apostles' decision doesn't include fornication -- did it need to? Paul is emphatic about that though, and he was right. We shouldn't need someone to tell us that. Anyone descended from Noah should know it.