Now we can understand what Yirmiyah was telling us. “Baruch hagever asher yivtach baHashem” – A person who trusts in Hashem has everything in his life taken care of for him. He doesn’t make himself crazy with effort. He knows his physical and spiritual well-being will be just fine and he lives a life of tranquility.
But Yirmiya’s main point is: “Vvehaya Hashem mivtacho.” That you have on Who to rely. Since Hashem is eternal, bitachon is eternal as well. No matter what happens in the world around you, bitachon is always there and will never fail you.
To illustrate this: Reuven is newly married, and his father-in-law Yaakov agrees to support him financially. Yaakov is a hard-working man who manages to feed his family and can occasionally afford some luxuries. Reuven relies on Yaakov, but in his mind he’s always concerned that maybe his father-in-law won’t be able to continue this arrangement, so he puts money aside now and sometimes worries about the future.
But let’s say that Yaakov was a man of means like Bill Gates. His son-in-law Reuven would never concern himself with financial worries, it would take a tremendous upheaval to bring down Yaakov’s empire!
Certainly someone who relies on Hashem for support has no worries. Hashem is always with us and He has complete control over all resources.