In this week's parsha, we begin learning about the plagues. What exactly is the lesson for us?
One idea is the fact that Hashem could have taken us out of Egypt and put the Egyptians in their place in a millisecond, but rather had a specific process in which he struck them and took us out. Why?
One idea is the concept of vihasheivosa el levavecha, "and you shall bring [Hashem] into your hearts." It is known how the baalei mussar were experts at giving over messages in a powerful, effective, and positive way. The Alter from Novardok z"l once sent a long-lost student a postcard with just one word written on it in big letters: א י כּה, "Where are you?" (this is the question that Hashem asked Adam haRishon right after the sin). The Alter from Slabodka z"l once turned off the lights when a talmid (student) came in and said assur l'histakul b'fnei adam rasha, "it is forbidden to stare in the face of a wicked man" (he did this because he felt that this was the specific treatment that this particular student needed, and he knew what he was doing). He once sent for Rav Hutner z"l (a bachur in yeshiva at the time) on Yom Kippur, and when he came near, he jumped back and said that he does not want to be in the same daled amos as him on this sacred day. The baalei mussar were geniuses in the nefesh ha'adam and the innerworkings of a person, and knew how to turn a person inside-out in order to reach his true potential and live a happy, fulfilled life. (This is all the product of proper hisbonenus [introspection and meditation], like the Ramchal speaks about in many places.)
Same thing with the plagues on the mitzrim: Hashem is teaching us in a very specific manner all about Himself so-to-speak, and how He runs the world (see Ramban).
