Our forefathers trusted in You; they trusted and You rescued them. They cried out to and they were saved; they trusted in You and they were not shamed. (Tehilim 22:5,6 – Esther’s prayer before entering Achashverosh’s chambers to plead for her nation.)
Esther was saying to Hashem: In You our forefathers, the generation who went out of Mitzrayim, trusted. Why should we be less deserving than them? If it is because they trusted in You and we didn’t, the truth is that they didn’t originally trust in You either rather, while still serving idols they cried out and were saved and only after their complete salvation did they trust in You and they were not shamed. This being the case, You should save us as well and we will also trust in You. (Commentary of RaSh Di Uzida, Megillas Esther 5:1)
It seems that even when one fails in placing his trust in Hashem, by telling Hashem that he will use His salvation as a means to strengthen his Bitachon in the future, this itself is a tremendous reason to attain Heavenly salvation. For after all, “The main reason the Torah was given to Klal Yisroel was so that they would place their trust in Hashem… for the essence of everything is complete Bitachon which is the sum of all the Mitzvos.” (Vilna Gaon, Mishlei 22:19)
This, in fact, is the very deal Esther made with Hashem that lead to our salvation in the story of Purim!
Other parts to this series: Inspiration in Bitachon