Your response was well thought out. You see what Paul was saying about sin being in the world before the law (of Moses) was given. What does Paul say about those who were not privy to Moses' law. Were they not a law unto themselves? Even going so far as to say those who knew nothing of God were without excuse because they could see God in the creation and knew He Is.
In Romans 2:12, it is far better to be judged by the Mosaic Law than to perish apart from it. In Romans 2:13, only doers of the law will be justified. In Romans 2:14, Gentile believers will by nature do what the law requires.
The quote above though kind of threw me. Are you saying that since Jesus lived and taught under the old law that we must now obey its articles as well? That goes directly against Paul's argument about the Gentiles. No to circumcision. No to feasts and holy days.
Yes, Christ was born under the law (Galatians 4:4), so he was obligated to obey it, and he was sinless, so he set a perfect example of how to walk in obedience to it, and those who are in Christ are obligated to walk in the same way he walked (1 John 2:6). I do not think that Jesus hypocritically preached something other than what he practiced or that he established the New Covenant in order to undermine anything that he spent his ministry teaching by word and by example, but rather the New Covenant still involves following God's law (Jeremiah 31:33). In 1 Corinthians 11:1, Paul instructed us to be imitators of him as he was of Christ, so I think Paul also taught obedience to the Mosaic Law by word and by example, and that is what we are also called to do. In Acts 21:20-24, Paul was rejoicing that there were tens of thousands of Jews coming to faith who were all zealous for the Mosaic Law and he took steps to disprove false rumors that he had been teaching against it and to show that he continued to live in obedience to it. In Acts 23:6, Paul still identified as a Pharisee, which is a sect of Judaism that observes the Mosaic Law. In Acts 24:24, Paul worshiped the God of his fathers, believing everything laid down in the Law and the Prophets, and God's law is His instructions for how to worship Him. According to John 12:44-50, we need to listen to Christ's words, so I don't think that Paul opposed anything that Christ taught by word and by example, but if you do, then you need to choose between whether you are a follower of Christ or a follower of Paul.
In 1 Corinthians 5:6-8, Paul spoke in regard to how Passover foreshadowed Christ by drawing the connection of him being our Passover Lamb, however, instead of concluded that we no longer need to bother with Passover, he concluded that we should therefore continue to keep it. In Acts 16:3, Paul had Timothy circumcised. In Acts 15:1, they were wanting to require all Gentiles to become circumcised in order to become saved, however, that was never the purpose for why commanded circumcision, so the problem was that circumcision was being used for a man-made purpose that went above and beyond the purpose for which God commanded it. So the Jerusalem Council upheld the Mosaic Law by correctly ruling against that requirement, and a ruling against something that God never commanded should not be mistaken as being a ruling against obeying what God has commanded as if he Jerusalem Council had the authority to countermand God.
Acts 15
10 Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear?
11 But we believe that through the grace of the Lord Jesus Christ we shall be saved, even as they.
In Deuteronomy 30:11-14, it says that God's law is not too difficult to obey, and in 1 John 5:3, to love God is to obey His commandments, which are not burdensome, so take your pick:
1.) God was wrong in Deuteronomy 30:11-14 and the Jerusalem Council was correct in Acts 15:10-11.
2.) God was correct in Deuteronomy 30:11-14 and the Jerusalem Council was wrong in Acts 15:10-11.
3.) They are both correct, but are not both speaking about the same law.
My vote is for #3 because they were speaking about things that had been added on top of what God had commanded, as I showed with Acts 15:1. Furthermore, the Psalms contain extremely high praise for God's law, such as with David repeatedly saying that he loved it and delighted in obeying it, so if we consider the Psalms to be Scripture and to therefore express a correct view of God's law, then we will also delight in obeying it, as Paul did (Romans 7:22), which means that the belief that the Psalms are Scripture is incompatible with the belief that God's law is a heavy burden that no one can bear. For example, in Psalms 1:1-2, blessed are those who delight in the Law of the Lord and who meditate on it day and night. We can't believe in the truth of these words while not allowing them to shape our view of God's law. The view that we have of the law matches the view that we have of the Lawgiver, which was certainly the case with David.
19 Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God:
20 But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
The "Jerusalem council" thought these things from the old law were sufficient. Would anyone say that these four "commandments" are the entire law of Christ? No, certainly not. We do not commit adultery or kill or steal or bear false witness not because Moses taught us but because (as you said) God has taught that from the beginning.
The moment that you recognize that those four laws are not an exhaustive list of everything that would be required of mature Gentile believers is the moment that those verses can no longer be used to put any sort of limitation on which laws Gentiles should follow. To love God is to obey His commandments, so saying that there are commandments that Gentiles shouldn't follow is saying that there are areas where Gentiles shouldn't love God. As stated, these four laws were a listed intended for new believers who were coming to faith, which they excused in Acts 15:21 by saying that they would continue to learn about how to obey Moses every Sabbath in the synagogues. It's kind of like how an employer doesn't require a new employee to memorize everything that they will ever need to know about how to do their job up front, but rather in order to avoid making it too difficult for them, they start by teaching them the basics with the understanding that they will continue to learn how to do the rest on the job.
We need to be clear that GOD'S law is what we follow. Not completely the same as Noah's time or Abraham's time or Moses' day or even Nebuchadnezzar's day though all have commonalities only the current agreement between us and God is valid today.
I follow Christ.
If the Mosaic Law teaches us about who God is and if we should live in a way that testifies about who God is, then we should obey the Mosaic Law. For example, God's righteous laws teach us about His righteousness, however, they do not exhaustively describe every aspect of God's righteousness, so any two sets of instructions for how to express God's righteousness are going to contain the same types of laws, but vary only in the degree of how thoroughly they describe the aspects of God's righteousness. However, God's righteousness is eternal, so all of the aspects of His righteousness that He taught to various people are all eternally valid ways to express His righteousness. So even if Noah knew about an aspect of God's righteousness that God did not reveal to Abraham, or vice versa, then we should still act in accordance with it if it is our goal to testify about who God is.