Our Rabbis teach us:
Eliyahu's school teaches: The world will last for six thousand years, two thousand of chaos, two thousand of Torah, and two thousand of the Mashiach" (Tal. A.Zara 9a),
the era of Torah begins with the actions of Avraham and Sarah
וְאֶת הֶַנֶּּ֖פֶשׁ אֲשֶׁר עָ שוּ בְחָָ֑רָן
(And they took with them ) the souls they converted in Charan (Gen 12:5)
When Avraham reaches the age of Fifty-two the two millennia of chaos end. The world that will later spend two thousand years preparing for Mashiach, undergoes a fundamental change between the parshot of Noach and Lech Lecha. The climax of Noach is the covenant between God and the world that promises the world will not be destroyed. Even in the darkness, when we awake, we can say "מודה אני " (I am thankful) , because the world has been purified enough that there will be no more mass destruction, there is hope רבה אמונתך .