if you believe that, you'll believe anything
(redirected from if you believe that you'll believe anything)if you believe that, you'll believe anything
That is obviously false. The phrase implies that if someone can't identify something that is so obviously untrue, they are apt to accept any falsehood. A: "My son said his teacher doesn't believe in grades, so they don't get report cards." B: "If you believe that, you'll believe anything!"