One who chases a career for its own sake is not considered one who trust in H'shem. The reason is he is putting his trust in his career and not looking at it as a means to an end. When it provides for him he applauds it, when it causes him a loss he scorns and abandons it.
pg 451
Nefesh Hachaim
The bigger the Tzadik the stronger his Yetzer Hara, to the point that his Yetzer Hara must pretend to be his Yeter Hatov to mislead him. The Yetzer Hara will try to convince him only Torah and Mitzvot with pure intentions are desired by GD. The Yetzer Hara's goal is to make the Tzadik feel inadequate and quit. He will try to trick him into thinking his learning is not worthy by GD if it is not of perfect L'Shma standards by bringing convincing arguments from the Torah and Mishneh. We all must be aware of this deceit and recognize H'shem's love for all our Torah learning and Mitzvah performance.
Prologue to Gate Four Chapter 4 pg 124/125
