The phrase "act of God" refers to a natural event or disaster that humans have no control over. It is often used to describe something like a severe storm, earthquake, or flood that causes unexpected damage or destruction. Full definition
Our economic problems were not visited on this country by some cruel act of god or blind force of nature. (politics.co.uk)
If one of the independent variables in an outcome, (besides an actual act of god), is prayer, then think about it... you do have a brain, right? (religion.blogs.cnn.com)
A synopsis will reveal any big problems in your story — e.g., the whole thing was a dream, ridiculous acts of god, a genre romance ending in divorce. (janefriedman.com)