Hadith: Allah does not wrong a believer in a good deed

عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ: قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: «إِنَّ اللهَ لَا يَظْلِمُ مُؤْمِنًا حَسَنَةً، يُعْطَى بِهَا فِي الدُّنْيَا وَيُجْزَى بِهَا فِي الْآخِرَةِ، وَأَمَّا الْكَافِرُ فَيُطْعَمُ بِحَسَنَاتِ مَا عَمِلَ بِهَا لِلَّهِ فِي الدُّنْيَا، حَتَّى إِذَا أَفْضَى إِلَى الْآخِرَةِ، لَمْ تَكُنْ لَهُ حَسَنَةٌ يُجْزَى بِهَا».
[صحيح] - [رواه مسلم]

Anas ibn Mālik reported: The Prophet (may Allah’s peace and blessings be upon him) said: "Allah does not wrong a believer in a good deed; he is given on account of it in this world and will be rewarded for it in the Hereafter. As for the disbeliever, he is given the reward for the good deeds he has performed for the sake of Allah in this world, and when he comes to the Hereafter, there will be no good deed for which he can be rewarded."
Sahih/Authentic. - [Muslim]

Explanation

Allah Almighty does not wrong the believer, even concerning a single good deed. He does not deny him its reward or diminish it, in the worldly life or in the Hereafter. By virtue of this good deed, he is given welfare and bliss in the worldly life, like family, wealth, removal of afflictions, and abundant sustenance. And Allah will give him its reward in the Hereafter as well. As for the disbeliever, Allah gives him the reward for his good deeds in the form of good things in this life. But when he goes to the Hereafter, he will have no reward, for all his good deeds had already been rewarded in the world, and nothing remains for which he can be rewarded or be saved from the punishment. A deed performed by a disbeliever can be described as a good one in accordance with his view of it; otherwise, his good deeds are not accepted by Allah or regarded as valid acts of piety, given their non-fulfillment of the requirement of faith. Or it can be called a good deed because it outwardly resembles a good deed performed by the believers. As for rewarding the disbelievers on account of their good deeds in this life, this is subject to Allah's will, as revealed in the verse that says: {Whoever desires this fleeting life, We hasten therein whatever We will to whoever We please.} This is the correct view in this regard.