rationalskepticism.org

You could simply say that you have no interest in their superstitious beliefs. If they say their beliefs aren't superstitious, point out that superstition is the belief in supernatural agency, and if they believe a god created everything, that is by definition a superstitious belief.

I've twice left preachers thinking about how to respond, and as I've walked away, reminded them not to step on any cracks in the pavement. On a remote coast path in Wales, I might be tempted to check that nobody is watching, then give the buggers a quick shove