Providence in LOTR?

[Bêthberry]

I found this quotation from Tolkien on grace and Providence on a private website and thought it would make a good addition to the discussion here. I don't have the Letters so I cannot verify the context.

No account is here taken of 'grace' or the enhancement of our powers as instruments of Providence. Frodo was given 'grace': first to answer the call (at the end of the Council) after long resisting a complete surrender; and later in his resistance to the temptation of the Ring (at times when to claim and so reveal it would have been fatal), and in his endurance of fear and suffering. But grace is not infinite, and for the most pan seems in the Divine economy limited to what is sufficient for the accomplishment of the task appointed to one instrument in a pattern of circumstances and other instruments. ~letter 156

Bethberry