The Gemara in Masechet Yoma 22B says, “Rav Huma says, ‘How often a person doesn't become sick, and doesn't realize (a man) that his Master helps him,’ meaning a person may have Siyata Dishmaya and not be aware of how many times he’s been saved. Rashi explains, “How reliant and guaranteed, he doesn't have to become sick with worry from any bad thing. If Hashem is helping you, you do not get have to get sick from worry about evil happening, because Hashem is taking care of you.”
What's the example?
David Hamelech sinned twice and he made it through, whereas Shaul made one mistake and didn't survive. Why? Because David Hamelech had help from Above and Shaul did not. The obvious question is, what's going on here? Is Hashem just picking favorites? David Hamelech gets help and Shaul doesn't? David Hamelech is great and Shaul is also great. It says that when Shaul became King, he was like a one year old, with no sins. So what's going on? Rav Bloch, in his sefer on Bitachon (page 31) explains that that's exactly the point. Shaul reached his greatness because of his purity and his lack of sin. Once he sinned, he dropped his level. On the other hand, David Hamelech didn't reach his levels. Of course, David Hamelech was a sadik, but that wasn't what it was about. David Hamelech was all about his reliance on Hashem. The entire Sefer Tehilim expounds upon that.
And therefore, he wasn't at all focused on deserving or not deserving. He might have had reasons to lose his Malchut, but he didn't.
Rav Bloch brings down a beautiful midrash on Tehilim chapter 141, where David Hamelech says, “I'm comparable to someone that had a judgment in front of the judge, and saw that everyone had lawyers there protecting them. So he tells the judge, ‘Everyone has lawyers. I don't have a lawyer. I have no one to represent me. I have no one to protect me. You’re the judge. I want you to be my protection.’”
David said, “Some people can rely on their own good deeds, and some people rely on the deeds of their forefathers. I'm only counting on You. I have no deeds. I called out to You to save me.”
So the person that has no focus on his deeds or zechuyot, or the merits of his father, is better off, because he's only counting on Hashem.
There’s a very interesting Gaon of Vilna, in his commentary on Nachum, (chapter 1, verse 7) where it says,
ט֣וֹב ה׳ לְמָע֖וֹז בְּי֣וֹם צָרָ֑ה וְיֹדֵ֖עַ חֹ֥סֵי בֽוֹ׃
Tov Hashem L’Maoz, God is good to the one who's Maoz on the bad day, and knows the ones that seek refuge in Him
Asks the Vilna, What is this Maoz and what is the the Hoseh Bo? He explains that the Maoz is the fellow that has his merits, or the merits of his fathers, and the Hoseh Bo, one who seeks refuge does not focus on merits at all. He just seeks refuge in God.
And therefore, he says, for the one that has merits and relies on his merits and his father's merits, Tov Hashem B’Yom Tsara/ God will be good to him when there's a problem. If he’s in a situation of a tsara/problem, God will protect him. But the fellow that seeks refuge in Hashem directly, “Hashem knows and supervises and protects this man, and he will never have a problem to begin with.” And that's why it doesn't even mention the words Yom Tsara regarding the person that is Hoseh Bo. This is a constant, repeating theme. There's an approach that goes on merits and demerits, and there's an approach that doesn’t focus on merits.
This second approach focuses on reliance on Hashem, that is not dependent on anything. And that is the Bitachon approach.
As Sefer Ikarim says (4th essay, chapter 47) There's a hope that he calls Tikvat HaHessed/that I hope to Hashem to save me based on Hessed alone, not based on any ability, responsibility or reciprocation. It’s just counting on Hashem’s kindness, like it says, “God is good to those that that hope to Him.” He says that what makes it difficult is that the person thinks to himself, “If I am not deserving, why should I get it?” And since he doesn't think he's deserving of this Hessed, he’s not really hoping fully. If he were hoping fully, he'd get it. But he's not getting it because it comes from his end.
And his words are,
“Tamid, Hashem always wants to bring bounty upon the person that's properly hoping,” but it's up to him. And he says, “The only reason why the Hessed doesn't come down upon him is because he doesn't hope properly.”
It's hard to hope when you don't think you're deserving.
But that's our job- to really build up our belief in Hashem’s Hessed, and in turn, our ability to hope to Him.