[Source: Likutei Sichos of the Lubavitcher Rebbe]
The word "shemot'' means ''names'', as in the verse '
'these are the name of the children of Israel who came to Egypt'' [Shemot 1:1]
A person's name is an extremely personal matter. Whenever a person hears his name called out, the word resonates in his heart, and lifts his spirits. People feel so strongly for their names that they will pay fortunes to have their names written on buildings, as they yearn for their identity to be perpetuated in stone.
In fact, a name is such a deep-rooted entity that, if a person faints, whispering his name into his ear can actually bring him back to consciousness.
Rashi comments [1:1] that naming is the best sign of affection. Seemingly there are greater signs of affection than mere naming. A parent can show love to a child through giving a gift, or through words of affection, or through physical embracing. Why did G-d show His affection to the tribes through repeating their names?
However, these other signs of affection are all relative to the situation at hand. For example, what might be a generous gift for one child would be an insult to another. Similarly, words of affection must be specific for a particular child at his level. And while a hug may always seem appropriate, it requires the presence of the child and his conscious alertness. Only the calling of a name breaks through these barriers and is applicable in all circumstances.
Consequently, when the Jewish people were immersed in the idolatrous culture of Egypt, they had few merits and so the only possible sign of affection was to repeat their names. This teaches us that G-d's love for a Jew is unconditional.
[Lubavitcher Rebbe]