This is one of the greatest lines by Tolkien. Filled with profound wisdom and reality for our everyday lives. I think about it often.
“Yet it is not our part to master all the tides of the world, but to do what is in us for the succour of those years wherein we are set, uprooting the evil in the fields that we know, so that those who live after may have clean earth to till. What weather they shall have is not ours to rule.”