As famine rages, a sharecropper makes a bargain with the landowner for food in exchange of his attractive wife, but the landowner, who is the Devil testing Man's Soul, also wants his innocent 14 year old daughter.

Good premise but the logline doesn't tell us what type of movie to expect.

What is the sharecropper's course of action? Does he grant his daughter, then tries to get her back?
Or is he fighting famine, refusing to give in to the Devil's demand?

A logline must give us a fairly good understanding of what type of action to expect for most of the movie (i.e. in Act Two).

If this is a character journey (which for some reason I believe it would be), we need to see what the sharecropper's weakness is. Is he overly pragmatic? Doesn't he consult his wife before doing the deal?

It would be better for the logline if some of these issues were clear.