But I had gradually come, by this time, to see that the Old Testament from its manifestly false history of the world, with the Tower of Babel, the rainbow at sign, etc., etc., and from its attributing to God the feelings of a revengeful tyrant, was no more to be trusted than the sacred books of the Hindoos, or the beliefs of any barbarian. The question then continually rose before my mind and would not be banished, — is it credible that if God were now to make a revelation to the Hindoos, would he permit it to be connected with the belief in Vishnu, Siva, &c, as Christianity is connected with the Old Testament. This appeared to me utterly incredible.
By further reflecting that the clearest evidence would be requisite to make any sane man believe in the miracles by which Christianity is suppoted, — that 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 simultaneous 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 eyewitnesses; — by such reflections as these, which I give not as having the least noveltry or value, but as they influenced me, I gradually came to disbelieve in Christianity as a divine revelation.
...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 of my friends, will be everlasting punished. And this is a damnable doctrine
from The Autobiography of Charles Darwin