At the Creation and during Noah’s time, the basic assumption was that the whole world would worship G-d.  This changed when Avraham arrived – from now on, his descendants alone would worship G-d:

“When the Highest One gave the nations their inheritance /

When he separated the sons of Adam /

He set the boundaries of the nations /

According to the number of the children of Israel/

G-d will now choose a group that will worship Him; the hope is that the whole world will follow in the footsteps of this group. The group to undertake this mission must pass three stages: 1) building a family; 2) “melting pot”; 3) the revelation at Sinai. The nation that succeeds in accomplishing these three stages will be the chosen nation, a nation that will be an example to the world of how to worship G-d.

How is Avraham’s character different from Noah’s? Why did Avraham succeed where Noah had failed? Avraham is called “Ha-Eitan,” “The One Who Stands Firm,” and also “Ha-Ivri,” (Bereishit 14:13) which the Midrash (Bereshit Rabbah 42:8) explains as meaning, “Avraham stood one one side against the world, which stood in the other side.” In other words, Avraham was independent and as firm as a rock.

Two things make Avraham special: He discovered G-d by himself, and he understood that it was not enough to believe as an individual, that there must be a whole nation that believes (Rambam Hilkhot Avodah Zarah 1:1-3).

Avraham’s strength in standing alone against the whole world, along with his project of establishing a nation which would worship G-d, helped him succeed where others had failed.

Sometimes we try to influence others by mixing with them and trying to influence from within, but sometimes we can influence others by creating an elite group that influences others by being an example. Our goal as Jews is not to assimilate with the nations and with the world’s culture, but to create a special nation that represents G-d in order to show the world the way to human perfection and holiness.