Reading through Rom. 9-11 and a dozen or so other passages one is left with the conclusion that the One New Man shares in the spiritual blessings of Israel, but the Gentile culture is not assimilated into or inferior to that of Israel. In fact it is very clear that the Mosaic Covenant is not the inheritance of the Gentiles- the Abrahamic one is.
Concerning the Mosaic Covenant, even for those who were God Fearers/Gentiles, it is interesting to see how frequently the Mosaic Law noted that even foreigners who were not apart of Israel were not bound to the Mosaic Code in order to love the Lord.
In line with what was noted about Abraham and the Abrahamic Covenant (of which the Gentiles are apart of more so than the Mosaic One), I think it'd be noteworthy to add that there was time between Gen 10:25 and the apperance of Abraham in the next chapter----and that's stated because many assu,e that there were not others out there like Abraham who shared his faith. ...but the scriptures make clear that many others were seeking the Lord in the time of the Patriarchs
I'm reminded of how Job himself was a righteous man after God whom God highly favored---with many scholars saying that Job actually existed way before Abraham did. The Israelite author presents Job as a person living in Uz, which is outside the borders of Israel itself ---and His piety (Job 1:1) exemplifies the ideal in Israelite wisdom and He invokes the name of Yahweh (Job 1:21). But at the same time, his relationship to Abraham's offspring remains a mystery. The events of the book seem to be set in the times of the patriarchs, Abraham, Isaac, and Jacob. The way Ezekiel 14:14 and Ezekiel 14:20 refer to Job along with two others apparently from ancient times enhances this impression....and so do the favorite names for the deity, God" (Hb. 'Eloah, the singular of 'Elohim) and "the Almighty" (Hb. Shadday), which seem more suited to the days before the Exodus 3:14 and Exodus 6:3 instances. The name Yahweh, the Lord, appear only in Job 1-2 and Job 38-42, with one lone exception in the middle of the book, 12:9).
Again, the prophet Ezekiel mentions Job along with Noah and Daniel, and this seems to imply that he took Job as a real perosn. This is also the implication of James 5:11. With what was noted by Ezekiel, its interesting to see Noah and Job listed together---as Noah and Job are well-known righteous men of the past (Genesis 6:9, Job 1:1)..and Noah existed before the era after the Flood. Its possible that Job either existed at the same time as Noah or came directly after Him. Just a thought, as it concerns those whom God chose to reveal His standards.
There were others who also followed the Lord as well outside of Abraham....as seen in how Melchizedek stood outside the covenant community and yet was a channel through whom God instructed his people. Genesis 14 is clear on how Melchizedek (king of righteousness) was a priest of the Most High....a priest-king linked to Jerusalem, seeing that "Salem" is possibly a shortened version of "Jerusalem" (Psalm 76:2) and is related to shalom, the Hebrew word for "peace" (Hebrews 7:2). ..
Jethro also comes to mind, though he's much farther removed from Abraham. As it concerns the view of the Midianites being "pagan" people ignorant of the ways of God, Jethro comes to mind since he stood outside of the Covenant Community...yet displayed uncanny knowledge of God. With Jethro, in Exodus 18, he was a priest of Midian (Exodus 3:1, Exodus 4:18)...and in light of the difficulty of both Egypt and the journey to Rephidim, Jethro's coming to meet Moses displays a relational posture of peace and encouragement, similar to when Aaron met Moses "at the mountain of God on his return from Midian (Exodus 4:27-31). Amazingly, after simply hearing about what the Lord had done on Israel's belalf, Jethro's words and actions represent a more faithful response than came from many of those who had experienced the events in Egypt (not to mention Egypt itself, as well as Amalek). For when he says, "Now I know that the Lord is greater than all gods" in verse 11, he echoes the purpose that the Lord said the plagues were to have for both Israel (Exodus 6:7) and Egypt (Exodus 7:5, Exodus 7:15). When Jethro brought burnt offerings and sacrifices and ate before God with Moses, Aaron and the elders, he prefigured the pattern of life that the Lord would reveal further at Mount Sinai (Deuteronomy 12:5-7). Moreover, Jethro was used by the Lord to help him find a faithful and workable way to have others bear the burden of judging the people and ensuring their well-being (Exodus 18:13-26).
Again, Melchizedek and Jethro, the father of Moses, stand outside the covenant community and yet are channels through whom God instructs his people. Much of the wisdom in Proverbs 22:17 to 24:34 bears close affinities to Egyptian wisdom documented from other sources. Isaiah declares that Cyrus of Persia is God's anointed who has been raised up to do God's will (Isa. 45:1).