I also read the short book Defeating Darwinism by Opening Minds by Phillip Johnson.
I have to confess my utter ignorance of scientific things. I don't know enough to make an argument based on well-developed scientific reasoning for or against Darwinian evolution. I can say that throughout my Christian life I have been a young-earth creationist without feeling the need to think too hard about it.
Lately I've felt the need to dig a little deeper. This book was a simple primer on the debate. Here's what I've gleaned so far:
1) Darwin's theory of evolution was never intended to be reconciled to a belief in the existence of a Creator God. Darwin actually said that if there was a Creator God then natural selection was null and void. It would have to be thrown out.
2) Darwin's theory is based largely on the mechanism of natural selection. When we look at what spurred all of the variations in the created order, Darwin's answer is natural selection.
3) Natural selection is a mechanism that cannot coexist with God as a Guiding Force in Creation. Things could have evolved, but they could not have evolved through natural selection if God did the selecting. I think this is what is meant by Intelligent Design.
4) If we cannot have natural selection and God, we have to choose between the two. Can we keep evolution and throw out natural selection? We cannot keep Darwinian evolution. At least Darwin says we can't.
5) Evolution is based on the idea that matter is all that exists. This is called Scientific Materialism. If matter is all that exists, then we don't have souls, and we don't have free will.
6) If we don't have free will, then moral choices become very complicated. Human beings are not more important than apes, dogs, birds, trees, water, rocks, anything. Even heinous crimes become relativized.
(As I reread the above list, I noticed that 1-4 all basically said the same thing. But I'm writing this disclaimer rather than editing because I want to go to bed.)