He didn't actually say that, but it does sound like something he'd've said doesn't it —and regardless I think it's true!
https://voltairefoundation.wordpress.com/2021/02/16/voltaire-on-capitol-hill-anyone-who-can-make-you-believe-absurdities-can-make-you-commit-atrocities/#:~:text='“Truly%2C%20whoever%20is%20able,sur%20les%20miracles%2C%201765).
He didn't actually say that, but it does sound like something he'd've said doesn't it —and regardless I think it's true!
https://voltairefoundation.wordpress.com/2021/02/16/voltaire-on-capitol-hill-anyone-who-can-make-you-believe-absurdities-can-make-you-commit-atrocities/#:~:text='“Truly%2C%20whoever%20is%20able,sur%20les%20miracles%2C%201765).