Nebulous "It" and Absolutes

[Child of the 7th Age]

Davem,

I am running out the door to work, but just wanted to raise one brief but critical question:

willingness to suffer on the individual's part doesn't excuse the one who inflicts that suffering.

I agree but exactly who is it that "inflicts" the suffering on Frodo? Tolkien seems to make it fairly clear in his writings that the suffering came because of Morgoth and Sauron who clung to their own plans for power or control rather than following along with the music that Eru had spelled out: that plus those Elves and Men who elected to follow a similar path for reasons of greed, immortality or whatever .

If Eru (or God) gives us free will to make our own choices, is he 'inflicting' suffering on us, or is he giving us the chance to function as mature beings in a very complex world?