Brachos 4 raises the question of why Ya’akov feared Eisav when Hashem had promised “u’shmarticha b’chol asher teileich”, protection in all circumstances. Surely Ya’akov did not lack bitachon! The gemara answers “shema yigrom hacheit”; Ya’akov trusted in G-d, but feared that he might have sinned and become unworthy of receiving G-d’s protection.
My wife showed me a beautiful Abarbanel on this issue. Abarbanel writes that there is no contradiction between Ya’akov’s fear and his trust in G-d’s promise. Trust in G-d cannot make a person impervious to the natural emotional reactions of worry and fear – that is not what bitachon demands. Bitachon means that despite having worries, one must be guided by Torah reason and knowledge, not by those worries. Ya’kov did fear Eisav, as any person would, but in his mind he never lost sight of the fact that G-d’s promise would protect him.
I think this Abrabanel provides a realistic model of bitachon. Most people think of true bitachon as some sort of state of nirvana through which one escapes life’s worries. I can’t deny that this idea is out there in seforim, e.g. the Chovos haLevavos seems to equate bitachon with “menuchas henefesh”, but at least speaking for myself, such a goal is so far removed from what I consider achieveable as to be of little practical relevance or value. I see the modern religious persona as a conflicted, tormented soul struggling to make sense of the world, not existing in a peaceful state of self assurance. The Abarbanel’s model of bitachon does not demand that we deny our worries and fears, our conflicted thoughts and emotions, but rather that we fulfill our religious duty despite those emotional doubts and turmoil.