It says in the Pasuk (Shemos 14:31 Beshalach)
וַיַּרְא יִשְׂרָאֵל אֶת הַיָּד הַגְּדֹלָה אֲשֶׁר עָשָׂה יְהֹוָה בְּמִצְרַיִם וַיִּירְאוּ הָעָם אֶת יְהֹוָה וַיַּאֲמִינוּ בַּיהֹוָה וּבְמשֶׁה עַבְדּוֹ
And Israel saw the great hand, which the Lord had used upon the Egyptians, and the people feared the Lord, and they believed in the Lord and in Moses, His servant.
Why is it that Klal Yisrael first saw what HaShem did, feared, and then had faith? Normally once a person sees they don't need to have Emunah as well. They saw already!
According to the different levels on which one can understand the Torah (P'shat, Remez, Drush, and Sod) how can this question be answered? (Please don't limit or hold back any answers that fall into any of the understandings of the Torah.)