If human beings were designed by a god, then their physical desires were too. However, physical urges can sometimes be excessive and get people into trouble. The most obvious example of these is sexual desires. Especially in the case of men, the natural instinct for sex can be very consuming and far more than what religions, as well as societies, teach is optimal.
The major religions have traditionally taught that sex is something which should be limited to the person one is married to and primarily, if not exclusively (until recently anyway), for procreation. If this is the will of a god, it does not appear he had this in mind when he designed the basic biological instincts of humans.
The average male produces around 175 million sperm per day (including the killer sperm to kill those from other men which god so thoughtfully included)! It is inexplicable that a designer who wanted people to be at all chaste and monogamous would include that feature. Men are simply not biologically set up to be satisfied with a single mate or with the frequency they are usually able to have sex. However, there are many animals, presumably less well designed than people, who are contented to mate for life and only have sex for procreation even though there is nothing to stop them from doing if far more often.
Some gorillas are an interesting example of this. Even though they have harems, they only mate with them when the females are ready to conceive (which is not very often). Of course, there are other animals on the other end of the spectrum such as chimpanzees that are very promiscuous. The question here is that if the designer of everything wanted people to act more like gorillas, why did not he design them more like them as far as sexual drives go?
Those defending their god might argue that sex is a divine gift for people to enjoy. However, it could still be enjoyable without being such a powerful desire on people. At the very least, why cannot people be programmed to be more satisfied with just one mate? If polled, it is safe to say that most people would be happy to give up some of their sexual drives for greater control.
Then, there are all the problems caused by excessive sex drive. How many destroyed marriages, deaths and other problems can be traced to men and women being unable to control those biological urges and doing stupid things they never really wanted to do? From rape, murder and child abuse, the amount of suffering caused by deprived sex drives is incalculable. While it is wrong to blame too much on sex drive and deny personal responsibility, there are certainly many times when it has made a good person bad and a bad person worse.
It seems a divine being could have programmed at least a part of the sexual urge into much better channels. Imagine what the world could be like if a portion of this desire people have for sex was instead diverted to wanting to help those in need.
While none of this makes sense if one looks upon people as having been divinely created, it makes perfect sense from an evolutionary standpoint. There are obvious reasons why sex drive would be amplified (at least to a certain point) in natural selection. Does it not make more sense to simply say people are the flawed products of evolution, a process that does not always produce the optimal results for human happiness, than the design of a perfect god?