וּפָחַדְתָ לַיְלָה וְיוֹמָם וְלֹא תַאֲמִין בְּחַיֶיךְ (כח, סו)You will be in fear night and day, and you will not believe in your life. (28:66)Rav Yehoshua of Belz zy"a explains this pasuk as follows:"And your life will hang before you" even though it was predetermined on Rosh Hashanah how much money you will earn this year (Beitzah 15A) and that amount is just "hanging" and waiting for you to take it."You will be in fear day and night" - you will nevertheless be afraid. The reason for this fear is because "you will not believe in your life" you will be lacking in emunah and won't believe that whatever Hashem decreed for you will come to you no matter what. If you would have the proper level of emunah, however, you would not be afraid at all and you would trust in Hashem to provide for you.וּשְׁמַרְתֶם אֶת דִּבְרֵי הַבְּרִית הַזֹּאת וַעֲשִׂיתֶם אֹתָם לְמַעַן תַשְׁכִּילוּ וגו' (כט, ל)And you shall observe the words of this covenant and do them, in order that you will succeed... (29:8)

This article explains Rav Yehoshua of Belz's interpretation of a pasuk, emphasizing that fear of livelihood stems from a lack of emunah, and true trust in Hashe

When There is Emunah There are no Parnassah Concerns:

Collected Thoughts on the Weekly Parshah From Rabbi Meir Isamar Rosenbaum shlita