At the Darwin centennial in Chicago in 1959, Sir Julian Huxley, perhaps the most influential evolutionist of the 20th century, made the following pronouncement:
"Charles Darwin has rightly been described as the 'Newton of biology': he did more than any single individual before or since to change man's attitude to the phenomena of life and to provide a coherent scientific framework of ideas for biology, in place of an approach in large part compounded of hearsay, myth, and superstition. He rendered evolution inescapable as a fact, comprehensible as a process, all-embracing as a concept" (Julian Huxley, Evolution After Darwin, Vol. 1: The Evolution of Life, 1961, pp. 1-2).
Darwin was not an outright atheist; he referred to himself as an agnostic. However, he did not always have these views. "Charles hadn't always thought about God or religion as a problem. In fact...both Charles and his father thought he was going to be a country parson" (Deborah Heiligman, Charles and Emma: The Darwins' Leap of Faith, 2009, p. 23).
Darwin attended Cambridge University to prepare for life in the clergy. "While at university, Charles read theology, not just on assignment but also for pleasure. He especially enjoyed the works of William Paley. He read Paley's A View of the Evidences of Christianity...Paley wrote about natural history, arguing that if you examined specimens carefully, you could see how beautifully they were created, how perfect they were in their adaptations.
"This to Paley was evidence of the existence of God and proof that God was the creator of all species. Charles thought these arguments were well-written, coherent, and logical. He did not, at that point, question Paley's premises about God's role in creation" (ibid.).
Darwin was also an avid student of natural history. After graduating from Cambridge, he had opportunity to serve as naturalist on the HMS Beagle—a trip that would last five years, ending in 1836. "While he traveled...Charles did go to church quite regularly, both to the services that his captain led and on shore whenever he got the chance. Some of the crew made fun of him for how religious he seemed...But natural history became his true passion and now, after the voyage, in 1838, Charles was having serious doubts about God and Jesus, about the Revelation, about heaven and hell...he had begun to reject God's role in creation" (ibid., p. 26).
A number of issues contributed to Darwin's doubt. "Many points were being argued about at the time. Three main elements of Holy Scripture were in question—the Genesis account of the creation of the world and the Fall of Man, the wrathful character of the God of the Old Testament, and the New Testament Revelation with Christ's promise of eternal life..."After rejecting a literal reading of the Genesis account of the Creation as he learnt about the vastness of geological time, Charles questioned other historical parts of the Hebrew Bible, and found that he could not accept the God of the Old Testament because he was described as a vengeful tyrant" (Randal Keynes, Darwin, His Daughter and Human Evolution, 2001, pp 47-48).
Darwin's doubts about religion are understandable in retrospect, at least for those who understand what the Bible really teaches. The fact is that some doctrines that caused him to doubt are not in the Bible. For example, he was particularly troubled about the doctrine of everlasting torment in hell.
Years later, he would write in his autobiography: "I can indeed hardly see how anyone ought to wish Christianity to be true; for if so the plain language of the text seems to show that the men who do not believe, and this would include my Father, Brother and almost all my best friends will be everlastingly punished. And this is a damnable doctrine" (quoted by Heiligman, p. 231).
In April 1851, Annie, the beloved daughter of Charles and Emma, died at 10 years of age after an extended illness. Charles decided not to attend her funeral because he believed he would gain no comfort from a Christian service. This event apparently slammed the door on any remaining faith Charles may have had. "After Annie's death, Charles set the Christian faith firmly behind him. He did not attend church services with the family; he walked with them to the church door but left them to enter on their own" (Keynes, p. 243).
Had Charles Darwin understood what the Bible states about heaven, hell, the resurrection of the dead and eternal life, he may well have never doubted God, Jesus Christ and the Bible in favor of evolution.
Someone else probably would have fashioned the theory of evolution, as the general idea was floating around in England at that time. But it might not have originated with Darwin. He admitted his idea was a theory, and he knew it contained gaps. Still he had faith in his theory that was greater than the faith necessary for him to believe in the God of the Bible as he conceived of Him.
In 1881, near the end of his life, he received a letter from a school teacher that stated, "If we deny the derivation of life from inorganic matter...the most probable alternative is the idea of an eternal or ever-living being filling all immensity with his presence, and breathing into the first animal the breath of life" (quoted by Keynes, pp. 316-317).
Darwin wrote back: "I hardly know what to say. Though no evidence worth anything has as yet, in my opinion, been advanced in favour of a living being developed from inorganic matter, yet I cannot avoid believing the possibility of this will be proved some day in accordance with the law of continuity...Whether the existence of a conscious God can be proved from the existence of the so-called laws of nature...is a perplexing subject, on which I have often thought, but cannot see my way clearly" (ibid.).