Are All Gentiles Evil in the Old Testament? Was it fair for God to judge Gentiles in the Old Testament when they didn’t have his Torah (Law)? Did they even know who he was or that he was the real God?

I don’t think it’s beyond the scope to believe God had contact with Gentile nations before Christ. There are examples in the Bible of Gentile nations having interactions with YHWH directly (like Balaam) and indirectly (through a prophet like Jonah). Also since we are all related (through Noah), they could have retained memories of the moral laws given between Adam and Noah’s time. Abraham himself is kind of a “Gentile” since Israel is his grandson and the Sinaitic covenant which distinguishes Jews from Gentiles has not been given yet. Abraham is disguised by the command to circumcise in Genesis 17. In the story of Jonah, we see some Gentile sailors respond, with repentance and sacrifice, to God’s attack via storm on their ship because Jonah uses it to flee from his assignment to Nineveh. Eventually, when Jonah did prophesy in Nineveh, they repented for their sins. In addition, we see God communicate with Gentiles like in Job, the wicked prophet Balaam (Numbers 22-24), and Melchizedek king of Salem, who was a high priest of God (YHWH) among the Canaanites (Genesis 14:17-20). God even sent Nebuchadnezzar to conquer the Israelites because of their sin. God even ensured that Nebuchadnezzar preserved Jehoiachin (son of Jehoiakim) by taking him captive in order to preserve the line of David in exile.

Legal Codes like the T’ien-ming (Chinese), Ur-Nammu (Sumerian), or Hammurabi’s Code (Babylonian) were the Gentile’s versions of the Noahide covenant, making gentiles accountable for moral sins like killing, lying, adultery, etc. In the story of China, they are given the Mandate of Heaven in the first dynasty known as the Xia. They were the first three dynasties, Xia, Shang, & Zhou, who got in trouble with a supreme being (the Shangdi) for failing to follow the “T’ien-ming,” or mandate of heaven (a godly instruction manual for law and order). After the first three dynasties, the Shangdi takes away the mandate of heaven and curses China into a time of conflict called the Warring States period, which ends when China is reunited in the Qin (Chin) Dynasty, marking the beginning of Imperial China.

These moral laws pre-existed the Mosaic Laws/Sinaitic Covenant and can be found in various legal codes in Ancient Near East as well as around the world. I believe the Gentile nations were held accountable to those moral standards, but not accountable for the ritual purity laws of the Sinaitic covenant which were designed to set Israel apart. In Conclusion, one could infer that they were judged by the moral laws only, and those that kept those laws were considered righteous according to the Noahide covenant standards. Those righteous Gentiles from before Christ would likely have received Christ if they were alive in the 1st century and it seems possible while he was dead for three days in Sheol (afterlife/grave) he ministered to them. Either way, they are considered worthy of participating in the first resurrection which is reserved for the righteous (Luke 14:14, 1 Cor 15:12-58, 1 Thess 4:13-18, Heb 11:32-35, Rev 20:4-6).