Why did Allah create death? And why do we die and leave our loved ones behind?

Allah created death and life as a test for humanity and for recompense in the Hereafter. What afflicts a person of grief, pain, and calamities is part of the nature of this world, and one must be patient. This world is short, followed by the Hereafter, the abode of recompense. Ibn al-Qayyim said that the existence of mixed pains and pleasures is an evidence that there are two abodes: Paradise for pure pleasures, and Hell for pure pains. Allah does not wrong anyone; rather, He greatly rewards the servant for his patience in trials, to the extent that on the Day of Judgment, those who were healthy will wish they had been among the most afflicted people in the world. Upon seeing the reward of patience in the Hereafter, the servant will forget all the misfortunes of this world. Therefore, one must turn to Allah, rely on Him, and not surrender to the whispers of Satan. For the fear of Allah and the good upbringing of righteous children benefit the servant greatly.