How does God's justice align with the varying ranks of people in this world and the hereafter, where one possesses wealth and enters Firdaws, while another has nothing and enters the lowest ranks of Paradise?

Paradise has varying degrees, and its inhabitants differ in them according to their deeds. This is a requirement of justice, for one who strove diligently is not like one who did not. The Hadith indicates that frequent prostration is a cause for attaining high degrees. The disparity in degrees in Paradise is due to the disparity in deeds in this world. A Muslim must submit to the actions of Allah Almighty, for He is not questioned about what He does, and He wrongs no one.