the motive for the sending of the prophets is the realization of justice among the people

In some verses and hadiths, the motive for the sending of the prophets and the sending down of the Holy books is the realization of justice among the people; As God says
We have sent Our Messengers with proofs, and sent them with the Book and the Scales, so that people might establish the Scale (of justice)
Hadid-25