Rabbah says that Ps. 112:7 can be interpreted in two ways (found on 60a). Could he mean that if we trust G-d, then our minds will be peaceful (personal change from the "inside out") and conversely, if we keep our minds peaceful in troubles that occur, our bitachon will be undisturbed (change from the "outside in"). Put another way, does Rabba mean that we can either first change our behavior, then our feeling, or first change our feeling, then our behavior?
Todah Rabbah
Rabbi Eli Mallon, M.Ed., LMSW, New City, NY, USA
Rashi understands that the Gemara is simply stating that someone who has Bitachon, realizing that everything Hash-m does to him is for his best, will not fear a bad tiding, as in truth there are no bad tidings. For many other explanations of this Gemara, see the commentaries on Ein Yakov who speak about this Gemara at length (ha'Rif, Iyun Yaakov, and Anaf Yosef).
All the best,
Yaakov Montrose