What is the sin of the evil human being who must necessarily exist in contrast to the good human being, given the universe's existence based on contradictions? And what are the references related to this matter?

The statement that the universe is founded on contradictions is incorrect. Rather, it is founded on integration, truth, and justice, as Allah Almighty said: "And Allah created the heavens and the earth in truth and so that every soul may be recompensed for what it has earned, and they will not be wronged." This is manifested in the integration of night and day, colors, the existence of good and evil for testing, the integration of rivers with trees, the planets orbiting the Earth to maintain its balance, and the sun as a cause of life. All of these are signs of integration and harmony. As for citing divine decree as an excuse, it is practically rejected, as humans defend themselves against injustice, which indicates their awareness of their will, ability, and choice. This applies to matters of religion and guidance.