Overview

Overview
The Qur'an states that even the smallest acts of the believers will not be wasted.

[A]nyone who has an atom's worth of goodness will see it and anyone who has done an atom's worth of evil will also see it.[Qur'an 99:7]
Those whose belief in God shaped their correct perception on life, and who did good deeds and are faithful will be tested in this world but will be rewarded in the hereafter if their deeds are deemed acceptable by Allah and vice versa.[Qur'an 2:62][5]

There are some translations of the Qur’an in which we read statements like these:

Surely Allah does not do injustice to the weight of an atom, and if it is a good deed He multiplies it and gives from Himself a great reward. S. 4:40 Shakir

And you are not (engaged) in any affair, nor do you recite concerning it any portion of the Quran, nor do you do any work but We are witnesses over you when you enter into it, and there does not lie concealed from your Lord the weight of an atom in the earth or in the heaven, nor any thing less than that nor greater, but it is in a clear book. S. 10:61 Shakir

The Unbelievers say, "Never to us will come the Hour": Say, "Nay! but most surely, by my Lord, it will come upon you; - by Him Who knows the unseen, - from Whom is not hidden the least little atom in the heavens or on earth: Nor is there anything less than that, or greater, but is in the Record Perspicuous: S. 34:3 Yusuf Ali