Hope in Hashem saves even the unworthy

תשועתם היית לנצח.

"You were their salvation forever."

From the Al HaNissim / Purim liturgy: Hashem was the eternal deliverance of Bnei Yisrael — a salvation whose effect endures for all generations.

שהי' ישועה בזמן ההסתר.

For it was a salvation in a time of concealment.

The miracle of Purim came during a period of hester panim, when Hashem's presence was hidden behind natural events.

לחזק כל הדורות השפלים.

To strengthen all the lowly generations.

Precisely because the Purim salvation came in concealment, it gives chizuk to every later, lowly generation that likewise lives without open miracles.

להודיע שכל קויך לא יבושו אפילו אותן שאינם ראוין.

To make known that "all who hope in You shall not be ashamed" — even those who are not worthy.

The lesson of Purim is that everyone who places his hope in Hashem will not be put to shame, even one who is not deserving on his own merits.

מ"מ החוסים בהקב"ה לעולם לא יבושו.

Nevertheless, those who take refuge in the Holy One, blessed be He, will never be put to shame.

Regardless of one's worthiness, the very act of taking shelter in Hashem guarantees that a person will never be shamed.

וכ"כ חזקו ויאמץ לבבכם כל המיחלים לה' כו'.

And so it is written, "Be strong and let your heart take courage, all you who wait longingly for Hashem" (Tehillim 31:25).

The pasuk calls on all who place their yearning hope in Hashem to be strengthened — the strength comes from the hoping itself.

פי' אפילו מי שאינו ראוי:

That is to say: even one who is not worthy.

The phrase "all who wait longingly for Hashem" deliberately includes even the person who has no merit of his own — his hope in Hashem is itself enough.

Summary: The salvation of Purim came in a time of hidden Divine presence specifically to strengthen all the lowly later generations. It teaches that anyone who places his hope and takes refuge in Hashem will never be put to shame — even one who is entirely unworthy on his own merits, for the very act of hoping in Hashem is what saves him.