Writer Ernest Hemingway grew up in a strong evangelical Christian home in Old Platte, Illinois. His grandparents were missionaries and his father was a devout churchman. His family conformed to the strictest code of Christianity, and as a boy and then man he was active in the life of his church, even serving as a choirboy.
Then came the first World War. He went away as a war correspondent and saw the death and despair that only war can bring. His youthful enthusiasm for Christianity soured, and gradually he rejected his upbringing and denied the validity and credibility of the Christ he once claimed to embrace.
While we don’t know all the details of Hemingway’s life, there’s a real possibility that he never developed a personal relationship with Christ, which is the heart of Christianity. Living in an environment, going through catechism, conforming to the codes, and expressing a general affirmation of the truth of scripture is not really what genuine Christianity consists of. At its heart it is believing in and following Jesus.