It states (Shemos 7:5) 'ה אני כי מצרים וידעו, "The Mitzrim should know that I am Hashem." It seems from this pasuk that the purpose of the makos was that the Mitzrim should know Hashem.
The Degel Machaneh Efraim (Va’eira וגם ה"ד) writes in the name of this grandfather, the Baal Shem Tov Hakadosh, "My grandfather z"l asked that it seems strange that Hashem would do all these wonders and miracles above nature only so that Mitzrayim should know Hashem. In my humble opinion, it is clear that the pasuk is referring to Yisrael, the Jewish people, those who [were at very low levels and] acted like the Mitzrim. They had sunk into their falsehood. Hashem said that He will become so revealed (with the ten makos) until even they [the Yidden who act like Mitzrim] will know Hashem, and they will know that there is nothing but Hashem."
We say in the Ani Maamins, מאמין אני ... "I believe with emunah sheleimah that the Creator, bless be His name, He created and He leads all creations, and He alone did, does, and will do all deeds." This is the emunah that Hashem taught us through bringing the ten makos.
