Which book of the Bible has the quote: "Do to others as you would have them do to you"?

So very many "Christians" don't seem to be following this in the USA but can't continue calling themselves "Christians" when they've taken Christ out of their religion.

This is the best way to live your life wether you are a Christian or not. What a shame so many who say they believe in Jesus don't follow this rule, think of the wars and deaths that would have been avoided.

I have always believed this. I speak to everyone, there are no Strangers!!!

so many goes against this and count themselves a Christianity followers.

that means dont do unto others what you dont want others do unto you

I was not sure. But sounds more NT than OT