I think the natural state of the Force means anyone can tap into it, but needs practice and training to use it effectively, and some are more naturally talented than others and use it instinctually.
But the Force has its own will, and can “raise up” someone (like Rey) in a crisis situation (“Darkness rises, and light to meet it”).
I’m with this except, maybe, that last part. I don’t like the idea that the Force can bend someone to do it’s will. Especially the Light side.
I also haven’t seen the movie, so that might not be what happens.
It’s pretty much explicitly stated in The Last Jedi. I’ll see if I can find the whole quote.
JEDIT: Here it is:
SNOKE: Darkness rises, and light to meet it. I warned my young apprentice that as he grew stronger, his equal in the light would rise. Skywalker, I assumed.
Maybe not explicit, but pretty close if you ask me.
And I don’t think it’s that the Force is bending someone to do its will, but bestowing unusual mastery of the Force on someone who can do the most to counter the darkness. Rey still has free will and can run away and not do anything if she chooses.