Judah's display of self-sacrifice for Benjamin convinced Joseph that his brothers had truly repented of their former attitude. He therefore revealed his true identity to them. The brothers were understandably afraid that Joseph would take revenge on them. Joseph, however, assured them that he viewed the entire episode as Divine providence and did not bear any personal grudsge against them.
Joseph said to his brothers,
"G-d sent me ahead of you."
Bereishit 45:7
When G-d arranged for Joseph to rule over Egypt, this included the mandate to positively influence it spiritually, as well. Therefore, when (in the following verse) Joseph alluded to his position and ability, he made it clear to his brothers that he was not acting as their emissaries, but as G-d's: "It was not you who sent me here, but G-d. He has made me...ruler over all Egypt."
Egypt is the archetype of all exiles, and Joseph is the archetype of all Jewish leaders. Thus, the ability to positively influence reality, even during exile, is vested in Joseph's heirs, the spiritual leaders empowered, and guided by them -- we too possess the ability to affect the entire world positively. We do this by encouraging our fellow Jews to embrace the teachings of the Torah, and by encouraging all humanity to embrace the Noahide laws -- in order to create a world of justice, goodness, and kindness.
From Kehot's
Daily Wisdom #2