There is an interesting letter from the Rebbe about bitachon in Likutei Sichos, חלק י״ד, page 359. The letter starts, the Rebbe writes to this person that you are describing to me the situation of your business, that you're a big baal chov, you owe a lot of money, etc., etc. Then the Rebbe says the main thing here is that according to what it says in sefarim, and especially in sifrei chassidut, I'm going to tell you something that everything depends on that. That מדת הבטחון, ענין הבטחון, that is the measuring stick of how connected and how davuk a person is with the Aibershter. And if the connection is full, complete, then there can't be any chesaron, because since you're connected to the Aibershter, and by the אייבערשטער למעלה there is no chesaron, you can't have any chesaron. And then the Rebbe continues, since you're asking my advice, so after the hakdamah that I did as you asked me, I read it by the Tziyun, by the ohel of the Frierdiker Rebbe, the Rebbe says, according to my opinion, you have to work with yourself, and he doesn't say just work with yourself, he says harvehn oif zich, work hard, toil on yourself, to strengthen your emunah in the Aibershter in the greatest form, in the strongest form. And the real ענין הבטחון is that even if you don't see any derech in nature, nevertheless it's beyond any doubt by you that for sure everything will be good, and ובטוב הנראה והנגלה לעיני בשר ממש, which is something that good that we could see. Which means, he says, in parnassah b'harvachah, in health, because לגבי למעלה, לגבי the אייבערשטער למעלה, so the inyanim of nature, even though things naturally don't seem to be good, are not important, they don't stop anything. And since a person l'matah, when he has the proper bitachon, picks himself up and puts himself a little bit at least beyond the earth, beyond the teva, meaning that he poel's by himself that because he's a Yid that has emunah, he is for sure b'tachlis that there is no baal habayit, no boss boss over him except the Aibershter. So he is able to be mamshich that down here should be the same. That down here, no inyanim of teva could have any influence, any bad influence, chas v'shalom. And I am sure, the Rebbe says, that the Aibershter will help that if only you will strengthen your אמונה בתכלית, you will see right away a change in the behavior that the Eibershter does with him, coming to business, etc., etc. And you'll see your situation will start getting better and better, un fun gut tsu noch beser, from good to even better, etc., etc. So here the Rebbe says that according to the level of the bitachon of the person, that's how much the Eibershter gives him. And the reason is, cause by having bitachon you're going beyond the nature, and beyond the nature there is no problem.

The Rebbe doesn't say this here, but I'll give you a mashal that if a person chas veshalom is drowning, so in דרך הטבע there's no way out of it. But if you're talking from the Eibershter's side, what's the difference legabei the Eibershter whether you're walking on land or you're on water? Well, bifshitus in teva, on water you can't stand and on land you could. Who made that? Who made that nature that you can't stand on water and you could stand on land, dry land? The Eibershter made it. So is he limited to it? So the Eibershter is beyond it. So if you have the real bitachon, then the Eibershter behave with us also beyond teva.