Mark Twain was an atheist American writer whose sixty books included The Adventures of Huckleberry Finn and The Adventures of Tom Sawyer. In his last book, Letters from the Earth, Twain wrote:
‘You have noticed that the human being is a curiosity. In times past he has had (and worn out and flung away) hundreds and hundreds of religions; today he has hundreds and hundreds of religions, and launches not fewer than three new ones every year… One of his principle religions is called the Christian. A sketch of it will interest you. It sets forth in detail in a book containing two million words, called the Old and New Testaments. Also it has another name – The Word of God. For the Christian thinks every word of it was dictated by God. It is full of interest. It has noble poetry in it; and some clever fables; and some blood-drenched history; and some good morals; and a wealth of obscenity; and upwards of a thousand lies.’
I just learned he wrote a book in 1903 called “Christian Science” where he mocked the movement and its founder. He had big issues with faith healing.