The Segulah of Bitachon:

We see that Hashem has put into the nature of the world that sorcery cannot harm the Jewish people. So too, He has instituted a natural fact that if one has genuine bitachon, he will succeed in whatever he does, even if he is doing a bad thing. This is as is said in the name of the Vilna Gaon zy "a; "If one has bitachon in Hashem, even if he is a thief digging a tunnel to rob a house, he will succeed with his robbery!" The Rov of Telshe, Rav Yehuda Leib Bloch zt'l writes (Shiurei Daas, Chelek 1, page 59) that this is because Hashem made the power of bitachon into a natural phenomenon. If one trusts in Hashem, he naturally will succeed at whatever he id doing, even if it is an aveirah.