How can God favor some people and deprive others, despite the the unity of the scale in the Hereafter?

Allah wrongs no one, and He is the Just, the Wise. He is not questioned about what He does. Allah has indeed varied His servants in giving and withholding, and in trials. However, He has also varied them in what He has obligated upon them according to their conditions and capacities, for He burdens no soul beyond its capacity. Trials come through good and evil to test the patience and gratitude of His servants. Furthermore, the deeds of the hearts and intentions affect the reward; for the poor person may attain the reward of charity by his intention, and the rewards of charities vary according to intentions and circumstances.