Why did God put the tree of knowledge of good and evil in the garden and......?

All of humanity’s suffering, pain, sorrow, agony, misfortune, affliction, and misery are fatal consequences of man’s fall. As a Bible believer, we can trace all back to the cause when the first man Adam sinned, which made the sin enter the world and put everything under curse. God is all-knowing, Why did He place the tree of knowledge of good and evil in the garden and command man not to eat from it, for in the day they eat from it, they will surely die? Why did God put a law that gave sin its power and caused the fall of man? Paul said: The law is the power of sin (1 COR: 15:56), and through law, sin was shown to be sin (ROM: 713).