Valar and Maia abilities?

[Inziladun]

Originally Posted by William Cloud Hicklin

I've always found it a helpful metaphor to think of Evil (= Melkor) in Arda as a drop of black ink in a glas of water: a core but concentrated globule of pure black, which gradually dissipates throughout the whole (cf. the phrase "the whole of Arda was Morgoth's Ring) until we get uniform grey (i.e. our own time).

Yet the grey is still a canvas upon which Ilúvatar paints.

'And thou Melkor, shalt see that no theme may be played that hath not its uttermost source in me, nor can any alter the music in my despite. For he that attempteth this shall prove but mine instrument in the devising of things more wonderful, which he himself hath not imagined.'

The Silmarillon Ainulindalë

To me, that suggests that Ilúvatar knew full well what Melkor would do, and had made Melkor with that "flaw" of character for a purpose. That purpose is unstated directly, but Eru said the above words in the presence of the other Valar, and they would take it as an article of faith that, as the Eldar later explained to the Dúnedain in Númenor, Eru did not "plant to no purpose", and that while they were expected to do their best to try and counter Melkor's acts, if they failed they were not to worry or overextend their powers, or, more importantly, their authority in fighting him.