The very first instruction (Torah) that YHWH gives to ALL MANKIND is to be fruitful and multiply, fill the earth and subdue it. YHWH does not just instruct Jews or even just Hebrews to do this. It is for all humanity - Jew and Gentile alike (Genesis 1:27-32).
After "the Fall" did the sin and death relate just to proto-Hebrew-Semites? No! ALL of humanity suffered. If all of humanity suffers then all of humanity is bound by YHWH's instructions. No one gets a free pass. Everything from the prohibition against slaying Cain on forwards relates to ALL RACES.
Genesis 6-9. All humans sinned. All humans except Noah and family are wiped out in the flood. Obviously all humans were held accountable for their behavior by YHWH....
Moving forward, after the flood. Nimrod in Genesis 10 defies YHWH and YHWH punishes him and all his people. Again, not a Jew or Hebrew among them. Still held accountable - all of them.
YHWH then waits 10 generations for Abram (later Abraham) to be born. Abram has to give up his idolatry as a member of the nations BEFORE being counted as a Hebrew. He and all his Chaldean Ur family and friends must journey with him, get circumcised, etc. Even people who want to do business with Abraham - like the Shechemites - must be circumcised. So, the whole Gentile circumcision thing did not just come up in Acts 15! (For that you can also read verses in Deuteronomy and Jeremiah chapter 9.)
Through Abraham ALL NATIONS are blessed; that is a continuous theme:
Genesis 18: 18 Abraham will surely become a great and powerful nation, and all nations on earth will be blessed through him.
Genesis 24: 1 Abraham was now old and well advanced in years, and the Lord had blessed him in every way.
Genesis 25: 11 After Abraham's death, God blessed his son Isaac, who then lived near Beer Lahai Roi.
Genesis 48: 15 Then he blessed Joseph and said, "May the God before whom my fathers Abraham and Isaac walked, the God who has been my shepherd all my life to this day,
Isaiah 51: 2 look to Abraham, your father, and to Sarah, who gave you birth. When I called him he was but one, and I blessed him and made him many.
Acts 3: 25 And you are heirs of the prophets and of the covenant God made with your fathers. He said to Abraham, 'Through your offspring all peoples on earth will be blessed.'
Galatians 3: 8 The Scripture foresaw that God would justify the Gentiles by faith, and announced the gospel in advance to Abraham: "All nations will be blessed through you."
Galatians 3: 9 So those who have faith are blessed along with Abraham, the man of faith.
But what many Christians forget is WHY they can be blessed through Abraham who, in a way, was a Gentile too before he was counted as Hebrew. In the NT, we are told over and over again that Abraham believed YHWH and it was counted to him as righteousness. But, what gets lost is HOW Abraham believed and HOW his faith was proven - that is by ACTION and OBEDIENCE:
Genesis 26: 5 because Abraham obeyed me and kept my requirements, my commands, my decrees and my laws."
In other words - KEPT MY TORAH! If it's good enough for Abraham, it's good enough for all the nations who get blessed by him on that same basis.
Genesis 22: 11 But the angel of the Lord called out to him from heaven, "Abraham! Abraham!" "Here I am," he replied. 12 "Do not lay a hand on the boy," he said. "Do not do anything to him. Now I know that you fear God, because you have not withheld from me your son, your only son." 13 Abraham looked up and there in a thicket he saw a ram caught by its horns. He went over and took the ram and sacrificed it as a burnt offering instead of his son. 14 So Abraham called that place The Lord Will Provide. And to this day it is said, "On the mountain of the Lord it will be provided."
But what about Moshe? Surely that whole Exodus thing and those rules were just for the Hebrews? Really? What does the Bible say:
15 The angel of the Lord called to Abraham from heaven a second time 16 and said, "I swear by myself, declares the Lord, that because you have done this and have not withheld your son, your only son, 17 I will surely bless you and make your descendants as numerous as the stars in the sky and as the sand on the seashore. Your descendants will take possession of the cities of their enemies, 18 and through your offspring all nations on earth will be blessed, because you have obeyed me."
Exodus 12: 37 The Israelites journeyed from Rameses to Succoth. There were about six hundred thousand men on foot, besides women and children. 38 Many other people (Hebrew: ereb rab = MIXED MULTITUDE, MANY NATIONS) went up with them, as well as large droves of livestock, both flocks and herds. 39 With the dough they had brought from Egypt, they baked cakes of unleavened bread. The dough was without yeast because they had been driven out of Egypt and did not have time to prepare food for themselves. 40 Now the length of time the Israelite people lived in Egypt was 430 years. 41 At the end of the 430 years, to the very day, all the Lord's divisions left Egypt. 42 Because the Lord kept vigil that night to bring them out of Egypt, on this night all the Israelites are to keep vigil to honor the Lord for the generations to come.
43 The Lord said to Moses and Aaron, "These are the regulations for the Passover: "No foreigner is to eat of it. 44 Any slave you have bought may eat of it after you have circumcised him, 45 but a temporary resident and a hired worker may not eat of it. 46 "It must be eaten inside one house; take none of the meat outside the house. Do not break any of the bones. 47 The whole community of Israel must celebrate it. 48 "An alien living among you who wants to celebrate the Lord's Passover must have all the males in his household circumcised; then he may take part like one born in the land. No uncircumcised male may eat of it. 49 The same law applies to the native-born and to the alien living among you." 50 All the Israelites did just what the Lord had commanded Moses and Aaron. 51 And on that very day the Lord brought the Israelites out of Egypt by their divisions.
By "foreigner" YHWH means the uncircumcised. But an "alien" who is circumcised may eat the Passover, because the same Torah applies to BOTH OF THEM. This statement "one Torah for Jew and foreigner" or "one Torah for Israelite and foreigner" appears many times. Many nations came out of Egypt and many nations were bound with Israel, but the covenant comes from YHWH THROUGH Israel.
Okay, so after Moses and Joshua many prophets come. The monarchy is established. The Temple is built for YHWH but is it just to be used by Jews? Let's investigate this:
Psalms 86: 8 Among the gods there is none like you, O Lord; no deeds can compare with yours. 9 All the nations you have made will come and worship before you, O Lord; they will bring glory to your name. 10 For you are great and do marvelous deeds; you alone are God. 11 Teach me your way, O Lord, and I will walk in your truth; give me an undivided heart, that I may fear your name. 12 I will praise you, O Lord my God, with all my heart; I will glorify your name forever. 13 For great is your love toward me; you have delivered me from the depths of the grave.
14 The arrogant are attacking me, O God; a band of ruthless men seeks my life-- men without regard for you. 15 But you, O Lord, are a compassionate and gracious God, slow to anger, abounding in love and faithfulness. 16 Turn to me and have mercy on me; grant your strength to your servant and save the son of your maidservant. 17 Give me a sign of your goodness, that my enemies may see it and be put to shame, for you, O Lord, have helped me and comforted me.
Isaiah 2: 2 In the last days the mountain of the Lord's temple will be established as chief among the mountains; it will be raised above the hills, and all nations will stream to it.
Isaiah 52: 10 The Lord will lay bare his holy arm in the sight of all the nations, and all the ends of the earth will see the salvation of our God.
Isaiah 56: 7 these I will bring to my holy mountain and give them joy in my house of prayer. Their burnt offerings and sacrifices will be accepted on my altar; for my house will be called a house of prayer for all nations."
Isaiah 66: 20 And they will bring all your brothers, from all the nations, to my holy mountain in Jerusalem as an offering to the Lord--on horses, in chariots and wagons, and on mules and camels," says the Lord. "They will bring them, as the Israelites bring their grain offerings, to the temple of the Lord in ceremonially clean vessels.
Jeremiah 3: 17 At that time they will call Jerusalem The Throne of the Lord, and all nations will gather in Jerusalem to honor the name of the Lord. No longer will they follow the stubbornness of their evil hearts.
Jeremiah 29: 14 I will be found by you," declares the Lord, "and will bring you back from captivity. I will gather you from all the nations and places where I have banished you," declares the Lord, "and will bring you back to the place from which I carried you into exile."
Ezekiel 5: 5 "This is what the Sovereign Lord says: This is Jerusalem, which I have set in the center of the nations, with countries all around her.
Zephaniah 2: 11 The Lord will be awesome to them when he destroys all the gods of the land. The nations on every shore will worship him, every one in its own land.
Haggai 2: 7 I will shake all nations, and the desired of all nations will come, and I will fill this house with glory,' says the Lord Almighty.
Zechariah 8: 23 This is what the Lord Almighty says: "In those days ten men from all languages and nations will take firm hold of one Jew by the hem of his robe and say, 'Let us go with you, because we have heard that God is with you.'"
Zechariah 14: 19 This will be the punishment of Egypt and the punishment of all the nations that do not go up to celebrate the Feast of Tabernacle.
Mark 7: 15 On reaching Jerusalem, Y'shua entered the temple area and began driving out those who were buying and selling there. He overturned the tables of the money changers and the benches of those selling doves, 16 and would not allow anyone to carry merchandise through the temple courts. 17 And as he taught them, he said, "Is it not written: "'My house will be called a house of prayer for all nations'? 17 But you have made it 'a den of robbers.'"