a galus of names

The gemara (Pesachim 50a) tells us that we are not allowed to pronounce Hashem’s name as it is written, but in the future, “bayom ha’hu yehiyeh Hashem echad u’shemo echad.”  We don’t perceive G-d’s actions as being in concert with his essence, so we use a different name for both.  As the gemara explains, we say different brachos on besoros tovos than on bad tidings, but in the future, we will see that it’s all yad Hashem for good. At the time of geulah, G-d and his name will be one.

“V’eileh shmos Bnei Yisrael ha’ba’im Mitzraymah…”  The start of Sefer Shmos describes the descent of the Jewish people into exile.  Just as the gemara describes with respect to G-d, when the Jewish people are in exile, how we are perceived / how we perceive ourselves is not in concert with our true essence.  The “names” of Bnei Yisrael, how we refer to ourselves and how we are referred to, went down to Mitzrayim and took on a different meaning, separated off from our true identity.  

(based on Sefas Emes)