How many of us when we are in need we make a promise with Allaah,that if He gives us such and such,or removes a difficulty that we will become righteous and change, but then break that promise, reflect upon the following aayaat:

“And of them are some who made a covenant with Allaah (saying): “If He bestowed on us of His Bounty, we will verily, give Sadaqah and will be certainly among those who are righteous.”

Then when He gave them of His Bounty, they became niggardly [refused to pay the Sadaqah] and turned away, averse.

So He punished them by putting hypocrisy into their hearts till the Day whereon they shall meet Him, because they broke that (covenant with Allaah) which they had promised Him and because they used to tell lies.”

[Soorah at-Tawabah]