Let's Talk Morgoth

[Eruanna]

why was Melkor evil? Was this part of Iluvatar's plan?

If we see Melkor and the other Valar as aspects of Iluvatar, then it makes sense that there has to be evil in order to create balance with good, perhaps Melkor was simply fulfilling his purpose.

Arda remade being better than Arda Unmarred, but he ultimately enriched the story of the world. Can you imagine the history of Arda without his plans and machinations?

This is an interesting point, Maédhros. Sometimes good comes out of evil. Certain things, like wars for instance, are thought of as bad things, but throughout history we can see that times of war have also been times of invention and innovation in both technology and medicine.