There is nothing purposeless in the ‘palace’ of the universe. Its ecological system is so complex and the parts comprising it are so interrelated to one another that the lack or removal of one of them can result in the destruction of the universe.
If the bacteria within trees were killed we would not be able to obtain fruits from trees. Every species even every thing has an important place of its own in the structure of the universe. Such a magnificent universe cannot be purposeless. It works to a moving time-line. As seconds point to minutes minutes to hours and hours to the end of the present day and the coming of the next one and days point to weeks weeks to months months to years and years to the end of a whole life-span existence has its own days in its every sphere and dimension and the life-span appointed for it will one day come to an end.
Also time proceeds in cycles. For example a scientist has established that corn is abundantly produced in every seven years and fish come in abundance in every fourteen years. The Holy Book points to this fact in Chapter Joseph. The life of existence as a whole has certain terms or cycles. The worldly life is a cycle or term the life of the grave is another cycle and the afterlife is the last cycle which has many cycles or terms of its own. The Holy Book calls each of them a day.
This is so because a day is the shortest unit of time-cycles. It corresponds to the whole life of existence in that daytime reminds of the worldly life with its divisions of dawn morning noon afternoon and evening corresponding to one’s birth and babyhood childhood youth old age and death respectively and that night resembles the intermediate life of the grave and the next morning the Resurrection.