Right now, this isn't really a thesis. A thesis states your intentions or your primary conclusion/opinion on something that you intend to elaborate on in an essay/article/etc. It should have much more information that your sentence here has. I think of a thesis statement as a roadmap-- it tells your readers exactly where you are going to take them.
Let's say that I want to prove that the main theme of the novel Jurassic Park is that you should never "play God" or fate. Here's what my thesis statement might look like:
"Through the use of irony and imagery, Michael Crichton makes his central message to the reader clear: humans cannot toy with Fate without severe consequences."
That is the thesis statement for an essay where I would use examples of the writer's irony and imagery to prove my point.
The best way to make your sentence a thesis statement is to be very clear about your goals in your writing. It's not an easy thing to do, but the best place to start is with a simple, clear message!