Becoming God's friends is not enough to empower us to reach our proper goal.
As mentioned earlier, God has been converting his foes into friends throughout history.
Maybe God hoped, by realigning enough of them, to bring mankind to the cultural maturity needed for fulfillment, at which point the Mediator's anthroposis would proceed smoothly, as originally planned.
But it turned out otherwise. The consequences of the defection were too rampant, comprising the wickedness of God's foes and the residual bad habits of his friends.
The ancient Hebrews had supposed that Israel, a nation specially called into being by God as the prime vehicle for his realigning work, would lead mankind to the cultural maturity needed for our fulfillment. But their prophets recognised that it was not to be; wickedness within Israel convinced them of this. They saw that more was needed, some "new covenant" in which the whole nation would be God's friends and those friends' habits would be more effectively transformed, leading to the prevailing of realignment throughout mankind. And they trusted that God would do this.
I remember my affliction and my wanderings, the wormwood and the gall. My soul continually remembers it and is bowed down within me.
But this I call to mind, and therefore I have hope. The steadfast love of Yahweh never ceases; his mercies never come to an end. They are new every morning; great is your faithfulness.
"The days are coming, says Yahweh, when I will make a new covenant with the house of Israel and the house of Judah, not like the covenant that I made with their ancestors ..., a covenant that they broke .... I will put my law within them, and write it on their hearts."
"It is too light a thing that you should be my servant to raise up the tribes of Jacob and to restore the preserved of Israel;
I will give you as a light to the nations, that my salvation may reach to the end of the earth."
Isaiah 49.6. (The prophet imagines God addressing a future leader of Israel.)
It is hard to articulate the reasons for believing this statement of a problem. It borrows much of its credibility from the following statement of God's solution. All I can say here is that I find those prophecies plausible, and invite the reader to proceed.
Back to God's way to save us.