An excellent way to develop a thesis statement is to explore the character development in this fine story and build your essay around these characters. While Zora Neale Hurston is noted for her strong female characters, in this story she imbues the character Joe with goodness and integrity. A strong thesis statement for an essay exploring both these characters might go something like this:
Although innocence and joy underlie the love of Missie May and Joe, the threat to their life together wrought by the fiendish Slemmons ultimately leads to growth in both characters as understanding, forgiveness, and new life bring their love to fruition.
Similarly, you might develop a thesis that announces your choice to use symbolism in your essay. Such a thesis might go like this:
Missie May and Joe are living a blissful married life in their Eden-like world when Slemmons, representing the serpent's intrusion in paradise, tempts Missie May, ultimately bringing about the need for forgiveness and redemption.
You can get a lot of good ideas for thesis statements by visiting the "Themes" link to Hurston's story (below).
One I can offer you, however, (and is discussed in the "Themes" page) is to consider the differences between appearance and reality. You might want to go with something as straight-forward as "The old adage "all that glitters is not gold" is certainly true in Zora Neale Hurston's story of two characters , Missy Mae and Joe, blinded by what-seems-to be. It will be take some time before reality takes precedence over appearance and true gold is realized to be something more intangible than tangible."