There was a builder who worked for a company building homes. When he got older, he wanted to retire. He went to the manager of the company and informed him of his intention to retire. The manager said he could retire, but under condition that he build one final home for the company.
The man accepted the condition and began building the home as quickly as he could so he could fulfill the condition and finally retire. However, the home was built shabbily; the doors were poorly hung and the walls were flimsy. He then rushed to the manager and handed him the keys to the newly built home.
The manager then informed him that this home was a gift to him from the company he had served for so many years. Needless to say, the man was shocked; he thought to himself, why didn't I built that home well, why didn't I make that the best home I ever built?
Similarly dear brothers and sisters, our worship, our prayers and our voluntary good deeds are for Allah. He asks us to do them, but on the Day of Judgement they will be ours, they will be ours to benefit from. Therefore, let us perfect our woship, because we will soon find out and realize that all these acts of worship (salah, fasting, qiyam, etc...) are for us.
يَا قَوْمِ إِنَّمَا هَٰذِهِ الْحَيَاةُ الدُّنْيَا مَتَاعٌ وَإِنَّ الْآخِرَةَ هِيَ دَارُ الْقَرَارِ
{O my people, this worldly life is only [temporary] enjoyment, and indeed, the Hereafter - that is the home of [permanent] settlement.}
(Surah Ghaafir - Verse 39)