It says להגיד בבקר חסדך ואמונך בלילות to tell your favor in the morning and belief at night. The meforshim explain when its going good, we can see the benevolence of Hashem, but when things are going badly, the only thing we can rely on is the belief in Hashem.
In context, emunah peshutah means that which we believe, but we cannot behold. It is what is. If I would say it works for me, that is evidence that I do not have enough. I think you got accurate answers.