Sorry for not publishing this sooner. I only got a chance to really start writing it about 4.5 hours ago. I kept putting it off.
Evolutionists and atheists, seem to ask,
If God really designed the world intelligently, then why did _______ turn out the way that it did?.
To be concise: the complexity of animals [people included], and plants, is a testament to creation, but defects of animals, and of plants, do not prove evolution. Read on, for my more detailed answer.
Let us examine bicycle water bottles. If you were to buy 1 of every kind of them, then you would probably notice that some of those water bottles do not do a good job. That was certainly the case for every water bottle that I have seen that was made for a bicycle. Do these defective water bottles prove that they were not created or designed? At best, you could say, that figuratively, the bottles were not designed, because they do such a poor job. To be precise, though, we know that these bottles are created through normal business decisions, and that they have been created by "intelligent" people. I use that term very cautiously. In business, sometimes we can serve the consumer better by offering a lower quality item. Therefore, a leaky bottle can be just fine, if used as intended: used only with water in a location where spillage does not matter. Lower quality bottles can cut costs, and make the product accessible in niche markets. We can debate endlessly about water bottles, and the business decisions behind them, but we cannot ever claim that bottles evolved through random chance, and/or by a non-creator action, just because they leak.
In the same way, atheists can debate about God not existing, but they cannot base theirs claims on our defects.
In conclusion of the topic of defects, we can say that defects do not prove that he does not exist. This is just life.
Speaking of life, let us look at this defect issue on a more personal level.
Do you have cancer? I feel sad to think that people have to suffer with it. I lived through much suffering myself. I may have Asperger's Syndrome. I have suffered in failure and loneliness for a long time. My mother has Parkinson's. The Bible speaks about a man born blind. All of these things fall under an umbrella called, "Why does God permit evil?". It is so that he can do his good work. It is a very cold answer to those who suffer, would you not agree? I think that I have a right to give that answer, because it is true, and because it accurately reflects the claims of the Bible, and because I suffer too.
That is sad news, but it is also liberating news. Ideally, if I tell you that your sufferings are supposed to be like that, regardless of what you have done, then it should imply to you that it is not your fault. Any rational person should spend some time evaluating whether his suffering and/or success are brought about by his own actions. At the end of it, if he can show that his sufferings were not his fault, then he can breathe a bit of a sigh of relief, knowing that he gave it some honest thought, and that he is not at fault.
Many people have suffered through curious problems. When they find out that there is a word to describe their sufferings, they suddenly breathe a sigh of relief, saying, "You mean they have a word for it??". They feel that way, because the word gives them a sense of normalcy.
In conclusion of this personal perspective, I want to underscore that suffering due to defects can be a life of success and purpose.