By giving freedom to human beings and balancing the natural tendency of motivation to decide the right and wrong pathways, God put them to trial!

Verses 118-119 of Chapter 11

If thy Lord had so willed, He could have made mankind one people: but they will not cease to dispute.Except those on whom thy Lord hath bestowed His Mercy: and for this did He create them: and the Word of thy Lord shall be fulfilled: "I will fill Hell with jinns and men all together."