Charles Darwin noted several problems with his own theories. Below is one of my favorites: 

“But then with me the horrid doubt always arises whether the convictions of man's mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey's mind, if there are any convictions in such a mind?” Charles Darwin – in a letter to William Graham dated July, 1881 

I believe Charlie’s question to be a good one. 

If we owe our origins to physical processes only, then the greatest thoughts of mankind are reduced to nothing more that impulses snapping between various synapses in our accidental brains. 

Nothing would matter, since there would be no transcendence. If we are merely physical, having come from nothing, and are destined again to nothingness at death, how could our present existence have any meaning at all? 

Through the years, I have had a great many discussions with folks who claim to be atheists. Without exception, they have utilized their powers of reason in attempts to convince me that their atheism is “truth” and that faith in God is silly. 

Atheism, however, naturally (no pun intended) argues that our existence is pointless, purposeless, being totally unintended. This being so, why argue the point? Why attempt to convince me of atheism if atheism means that nothing matters? 

They betray themselves. Reason tells us all that we matter, thus even atheists argue, and militantly so, for conformity to their faith. 

I would ask them, as Darwin himself postulated, “Would any one trust in the convictions of a monkey's mind, if there are any convictions in such a mind?”