Personally, I think you could better than the four posted. The first one is incredibly cliché and boring, variations of which have been done before. The second one is too Bible-thumping, and those who have been damaged by Organized Religion will find this title a major turn-off. The third one is too cutesy, and for what I've read of the previous three books, this does not even come close to the quiet elegance needed. The fourth is the least noxious but the least specific.
Having ran a publishing company that put out 5000+ titles (in which most I personally chosen the titles and virtually all the cover work), I have had too much experience. So I've done you a favor. I bought all three previous titles and will read them before emailing you some other ideas. You don't have to accept any of them, but they might inspire you to find one of your own.
Title and cover work are the first impression of any book. You definitely can do better.