The more we know of the fixed laws of nature the more incredible do miracles become, — that the men at that time were ignorant and credulous to a degree almost incomprehensible by us, — that the Gospels cannot be proved to have been written simultaneously with the events, — that they differ in many important details, far too important as it seemed to me to be admitted as the usual inaccuracies of eye-witnesses; — by such reflections as these… I gradually came to disbelieve in Christianity as a divine revelation.
~ Charles Darwin (born: 1809-02-12 died: 1882-04-19 at age: 73)

When Darwin started his journey on the Beagle, he had been studying for the clergy, and had no doubts about the absolute truth of every line of the bible. It was having a deep look at nature that shattered his belief.