Russell, in Why I Am Not a Christian, critiques the Design Argument for God's existence and rejects it, giving him yet another purported reason to remain a-Christian. Russell writes: "everything in the world is made just so that we can manage to live in the world, and if the world was ever so little different, we could not manage to live in it. That is the argument from design."
Russell then argues that, like Richard Dawkins, Darwin's evolutionary theory shows us that apparent design can be explained without reference to a Designer God. What can we say to this?
I would first point out the existence of theists such as Francis Collins and Kenneth Miller who also agree with evolutionary theory. Collins and Miller make powerful cases for the acceptance of evolutionary theory while not eliminating the existence of God.
Secondly, we still have scientists who are interested in intelligent design theory. And we still have scientists who have questions about macroevolution. Note: ID theory is greatly despised by a number of scientists who are very vocal about this. One's position as a scientist could be in jeopardy if one raised questions about natural selection. Even the suggestion that one might like to at least investigate the claims of ID theorists can be enough to bring down on oneself a desert storm of ad hominem abusives. For some rational dialogue (with an admittedly theistic bias, yet containing essays by Wesley Elsberry and Nick Matzke, as well as atheist Michael Ruse) try something like this.
Philosophically it's significant that former philosopher-atheist Antony Flew has been persuaded by a version of the design argument and has come to accept the existence of a God. It was humorous to see the reaction of a few atheists (not all, by any means; and probably a number of them don't really care since they aren't interested in "evangelistic atheism" and wearing "I Ride the Atheist Bus" t-shirts). These few were scrambling to analyze Flew's mental capabilities. Evangelistic atheism simply in unable to comprehend that one could be a "bright" philosopher or scientist and still believe in God.
As for Russell, he was not familiar with anthropic coincidences and the fine-tuning argument which states that the fine-tuning of the unverse is not improbable on theism but is very improbable on the atheistic single-universe hypothesis. It's this latter argument that especially interests me.
Russell continues: "When you come to look into this argument from design, it is a most astonishing thing that people can believe that this world, with all the things that are in it, with all its defects, should be the best that omnipotence and omniscience have been able to produce in millions of years. I really cannot believe it. Do you think that, if you were granted omnipotence and omniscience and millions of years in which to perfect your world, you could produce nothing better than the Ku Klux Klan or the Fascists?"
I find this reasoning unpersuasive. Since Russell cannot see sub specie aeternitatis, he's in no position to judge that we do not live in the best of all possible worlds. And even if he could make that judgment, it is not clear that on Christian theism we should be concerned to show that we live in the best of all possible worlds, since whatever our world once was it has long since fallen from that state. Precisely, we do not live in the best of all possible worlds. The KKK and Fascism exist because we have been given free will. See here, for example, the arguments of Alvin Plantinga (his work on evolutionary naturalism) and Greg Boyd.
Russell's criticism here is facile and unstudied. He has yet to give me any significant reason as to why I should not remain a follower of Jesus.