Certain believers think a good comeback to an atheist who expresses the lack of evidence for any divinity is to ask why he believes in gravity. Gravity, the believer says, just like God, is invisible and everywhere. Most people believe in it without evidence, so why not believe in God?
Here is an example:
There are many good answers, but I am interested in how people in this forum might respond to the argument. It has been said that when Newton introduced the notion of a gravitational force, he was accused of bringing the occult into science.