"I never gave up Christianity until I was forty years of age....it was "not supported by the evidence"--Darwin
When he married Emma Wedgwood in 1839 he confessed to her that he was an agnostic. It broke her heart.
"During these two years I was led to think much about religion. Whilst on board th
e Beagle I was quite orthodox, & I remember being heartily laughed at by several of the officers (though themselves orthodox) for quoting the Bible as an unanswerable authority on some point of morality. I suppose it was the novelty of the argument that amused them. 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, rainbow as a 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 Hindus, or the beliefs of any barbarian."--Darwin
Another source of conviction in the existence of God, connected with the reason and not with the feelings, impresses me as having much more weight. This follows from the extreme difficulty or rather impossibility of conceiving this immense and wonderful universe, including man with his capacity of looking far backwards and far into futurity, as the result of blind chance or necessity. When thus reflecting I feel compelled to look to a First Cause having an intelligent mind in some degree analogous to that of man; and I deserve to be called a Theist.
"This conclusion was strong in my mind about the time, as far as I can remember, when I wrote the
Origin of Species; and it is since that time that it has very gradually with many fluctuations become weaker. But then arises the doubt–can the mind of man, which has, as I fully believe, been developed from a mind as low as that possessed by the lowest animal, be trusted when it draws such grand conclusions? May not these be the result of the connection between cause and effect which strikes us as a necessary one, but probably depends merely on inherited experience? Nor must we overlook the probability of the constant inculcation in a belief in God on the minds of children producing so strong and perhaps an inherited effect on their brains not yet fully developed, that it would be as difficult for them to throw off their belief in God, as for a monkey to throw off its instinctive fear and hatred of a snake.I cannot pretend to throw the least light on such abstruse problems. The mystery of the beginning of all things is insoluble by us; and I for one must be content to remain an Agnostic."---Charles Darwin
So, your argument that he was a Christian is thin. If you want to address his earlier days as a younger man, he was Anglican, yes. But he grew into atheism and agnosticism fluctuating. He was at the very best, an agnostic, not a Christian.
I'm not saying evolutionary faith MUST imply a jungle mindset to societies, but we must admit it can. Hitler is a great example.
The idea that evolution comes from atheists is patently false. Why, Charles Darwin himself was a Christian!
Believing that evolution happens does not immediately imply that we should apply the law of the jungle to our societies. Even biologist and atheist Richard Dawkins admits this would be a terrible idea.