Most people have an almost child like mentality: if I do good deeds and do what Hashem wants, why does Hashem not give me what I want or what I ask for?
And we tend to become angry, moody, resentful, disappointed when our expectations and wishes are not realized etc.
Pesach is the time to free ourselves from wrong mentalities. We need to open up and see life from a bigger perspective.
For example, suppose a person struggles all their life with making a decent living. They simply see no success in whatever they try to do. Such a person may start to feel angry, wondering why their good deeds are not rewarded more richly (pardon the pun).
And people may feel that Hashem owes them something. After all, they are doing mitzvoth, trying their best, why is it Hashem does not answer their prayers the way they want?
Well, it is time to break out of that mentality.
A person who struggles making a living may be going through that hardship because something worse may have been decreed and out of Hashems kindness He made an exchange: instead the person would struggle with parnassa. So it is actually a kindness.  So many things in life are exchanges: something worse was meant to happen and instead  Hashem in His mercy changes those things to a lesser suffering, to a situation that is easier to bear even if it is difficult.  And the truth is whatever suffering a person goes through in this world takes away suffering in the next world.
Every kindness and blessing we have in life we need to look at as an underserved gift from Hashem.  We need to see things as blessings, as positive situations.
With that attitude our perspective in life changes tremendously. We become grateful, appreciative,  humble.
When the yidden left mitzraim and came to the yam suf (the sea) and they saw the Egyptians pursuing them, they started to complain, asking why Hashem brought them out of Egypt to die in the desert. They could only see things in a negative light.
But when they crossed the sea to safety and saw the positive goodness in everything Hashem did, they sang shira, they sang praises to Hashem.
We need to try to see the good in everything now and already sing praises even before we see the miracles and the good. So even when things are difficult, try to sing praises and be happy because when Hashem sees you happy despite any problems, He will make things good in a way that you can appreciate and see, just like the Jews at the yam suf.
And may we very soon merit the complete redemption when our eyes will open and we will truly see our Creator and understand the purpose within all suffering and we will see the truth and
G-dliness in the world.
Today Yud Aleph Nissan is the birthday of the Lubavitcher Rebbe. He said once that when he was still a very young boy even before beginning cheder he was dreaming of the day when all Jews would be redeemed from galus, exile, and would understand the purpose for all suffering that the Jews have endured for so many thousands of years. Now on the Rebbe’s birthday may we all make good resolutions to add something in Torah and mitzvot and may that bring the true and complete redemption with Moshiach tzidkenu.