"G‑dliness is everything. Everything is G‑dliness."
-Baal Shem Tov.

Each of these paths contains what the other is missing:

Follow the path of "G‑dliness is everything" and you arrive at a place where even the darkness shines, for it too has divine meaning. And so it ceases to be darkness; the world is filled with light.

But you have not changed the world; you have left the world behind you. In this place, there is no world. There is only G‑dliness. Come back to the world and you will find the darkness stubbornly in its place.

That is the story of Abraham and Ishmael. Ishmael reformed himself during his father's lifetime. But as soon as his father died, he once again fell away.

So you take the path of "Everything is G‑dliness." You search within the dark earth and the mud, knowing that you will find sparks of G‑dliness hidden there. But the darkness itself, the thick clay and coarse sand in which you could find no glimmer of light awaiting you, that remains darkness.

That is the story of Isaac and Esau. Esau's head, we are told, rests on Isaac's lap in the cave. But his body remains out in the field.

The path of Jacob is to not follow any single path, but to travel in two opposite directions at once. To know a G‑d who is at once both beyond and within.

To Jacob, darkness and light are one. Eventually, Jacob will redeem Esau.

Likutei Sichot vol. 15, pp. 191-199.