Allah will definitely materialise for him what he asked for! (beautiful dua)

"O Allah! Make my religion, which is my strength and invincibility, good for me; and make my world, wherein is my livelihood, good for me; and make my hereafter, which is my final abode, good for me. And make my living an increase for me in all that is good, and make my death a repose for me from every ill.[Muslim reported it][1]

If the slave says this du'a, which entails seeking the betterment of his future both in terms of his religion and his worldly affairs, if he says that with a mindful and aware heart, and a true and sincere intention, coupled with an earnest struggle to achieve it, Allah will definitely materialise for him what he asked for and had hope in and struggled to achieve as a result of this, his worry will change to happiness and delight.

And also his saying:

"O Allah! It is Your mercy that I have hope in, so do not leave me to myself even for the blink of an eye, and make good my affairs, all of them; there is no god worthy of being worshipped but You."[Abu Dawud reported it, with a sound chain of transmission].[2]

Taken from the book: Useful-ways-of-leading-a-happy-life- By imam-as-sadi
Chapter Four: Forgetting The Unpleasant Things That Have Passed