In the Torah portion of Vayechi

In the Torah portion of Vayechi, Jacob blesses Joseph's two sons who were born in Egypt, Menashe and Efraim. These names were chosen by Joseph because they alluded to his circumstances in Egypt at the time when they were born.
Joseph named his firstborn Menashe, "For G-d has made me forget (nashani) all my troubles, and even my father's house." Far from home, Joseph was in danger of assimilating. Yet he remained connected to his people and to G-d. In choosing the name Menashe, Joseph indicated that he had, in fact, not forgotten his father.

Joseph named his second son Efraim, "For G-d has caused me to become fruitful (hifrani) in the land of my affliction." Not only have I not been influenced by the Egyptians, Joseph was saying, but precisely here, "in the land of my affliction," I established a family, became wealthy and made spiritual progress.

Menashe is symbolic of the bond Joseph shared with his father and the deep yearning he continued to feel for him.

Efraim is symbolic of Joseph's success in Egypt, a land that was vile and depraved.

Our situation in exile is similar to that of Joseph in Egypt. In exile, we are far from our Father's house - the Holy Temple - and G-dliness is concealed. What can we do to overcome our predicament? How are we to conduct ourselves during our sojourn in "Egypt"?

The answer is to learn from Joseph, and emulate him.

On the one hand we are obligated to remember our "Father's house," to yearn for the Holy Temple and G-d's closeness. A Jew must never resign himself to the exile. Rather, we must always look forward to the Redemption, continue to observe Torah and mitzvot (commandments), just as Joseph refused to acclimate himself to Egypt and named his son Menashe.

On the other hand we must always remember that it is precisely in exile, where poverty of the spirit prevails, that we must remain strong. Just as Joseph remained righteous and flourished in the land of his "affliction," so too must we spread Judaism and foster the belief in G-d precisely in a world that does not recognize His greatness.

When Jacob blessed Joseph's sons he placed his right hand on Efraim's (and not Menashe's) head, saying, "His younger brother shall be greater than he." For even though Menashe was the firstborn, and the beginning of our service must be the longing for our Father's house, the main objective of our service in exile is expressed in the name Efraim: an increase in Torah and good deeds, thereby causing G-d's Name to be known in the world. By emphasizing this aspect we will merit G-d's light to shine, even within the exile.