In The Merit of Temimus, One Acquires What He Needs With Ease:
The Vilna Gaon zy”a (Sefer Aderes Eliyahu), on the verse: ”V’eitz hadaas tov v’rah” (and the tree of knowledge of good and bad), states that this infers that having knowledge of what is or isn’t good is a very bad thing. He explains that the more simple and unquestioning a person is, the better it is for him. The bigger tam a person is, the better life will be for him, as is stated in Tehillim (119:1): “Praiseworthy are those who walk with temimus.”
He adds that we see that the Torah praises Noach, Yaakov and Iyov for having the midah of temimus. He explains that the more a person disassociates himself from worldly matters, the more he can connect to Hashem. If someone toils to obtain something through earthly means, he will have to put in a lot of effort. But if someone relies on Hashem, he will obtain the same thing with ease.
We can learn from this that one who serves Hashem with temimus will end up getting whatever is destined for him, without the need for excess toil and potential sins, such as theft and trickery.
