I think that all nations knew somehow about the Only and True God, my friend.
What I say is that God did not give all nations the same specific ritual laws, or used the same terms and symbols, or social and community norms, as part of his covenants, promises or plans.
Ancient Chinese didn't measure time in weeks, and we have absolutely no historical evidence that God had sent any messenger or prophet to the Chinese to encourage them to keep the Sabbath... and no evidence within the Bible that God condemned foreign nations for violating the Sabbath.
In addition, God could give to the same nation, different rituals or signs of His Covenant at different historical times.
For example, Jesus explicitly commanded his Jewish disciples to baptize others, but Moses did not command that. Did he?
God told Abraham that circumcision would be an "everlasting covenant" (Genesis17:13). So important, that people rejecting circumcision would be "cutt of" from the nation (17:14). However, centuries later, Paul declares it optional, irrelevant if you have circumcised your heart.
We can discuss the commandment of keeping the Sabbath in a separate thread if you are interested, Studyman.
Circumcision of the heart was always the requirement from God, in my view. To rule over/cut off the Flesh (Emotion/desire/lust etc.) was a command from the beginning. Cain committed the Sin of hating his brother without a cause. God instructed Cain that he would be accepted, like Abel, if he turned away from his sin (hate for his brother), and rule over the hate (Did well).
Abraham was Spiritually circumcised long before God gave him the Token between him and God. How would men know Abraham was circumcised, or Caleb, or Zacharias? Did they go around flashing their nakedness to show their circumcision? I don't think so. Everyone knew it was a Sin to look on the nakedness of their father. No, it is a private matter between God and man. The Israelites rejected the meaning of Circumcision as Paul exposed in Romans 3 and created their own religion that was called "The Circumcision". Paul exposed them, claiming that the True Church of God is the true Circumcision, as he declared, "We are the Circumcision".
This world's religious system "USES" parts of God's Word to deceive people, just as the serpent quoted "some" of God Word to deceive Eve. The overwhelming tradition of this world's religious sects and businesses is to "USE" Circumcision as a tool of justification to reject God's Judgments, His definition of Holy, Just, Clean and Good. Paul never did this. He "Promoted" Circumcision of the heart noting that the Physical act of Circumcision is profitable "If" a man "Yield's himself to God". But if a man partakes of the physical act, without obedience to God from the heart, his circumcision is made "Uncircumcision". This is what the Law and Prophets teach, for those interested in Seeking God's Truth as defined in the Holy Bible.
Since I have "Yielded myself" to God and His Judgments, Statutes and Commandments with all my heart, I don't need to justify rejecting them. Instead, like Paul instructed, I study the topic to find out why God instituted this Token between Him and man. In other words, I seek "for doctrine, for reproof, for correction, for instruction in righteousness" in the Holy Bible inspired by the God who instituted Circumcision, and this so "That the man of God may be perfect, throughly furnished unto all good works" which is what God Commanded of me".
Baptism is a similar topic. Moses most certainly promoted "Baptism" as God had intended it to be used.
Acts 22:16 And now why tarriest thou? arise, and be baptized, and wash away thy sins, calling on the name of the Lord.
Ex. 29: 4 And Aaron and his sons thou (Moses) shalt bring unto the door of the tabernacle of the congregation, and shalt wash them with water.
Luke 3: 16 John answered, saying unto them all, I indeed baptize you with water; but one mightier than I cometh, the latchet of whose shoes I am not worthy to unloose: he shall baptize you with the Holy Ghost and with fire: 17 Whose fan is in his hand, and he will throughly purge his floor, and will gather the wheat into his garner; but the chaff he will burn with fire unquenchable.
Indeed, these are good discussions to have among men seeking God's Truth.