Based on science alone, God wouldn't exists.
However, here's some interesting points (at least to me):
1) We were made by "accident" whether or not a knowing God exists. If we were created by thoughts of a god, then certainly that was accidental creation because we would never exist if a god hadn't thought of it. I view this as no difference from being "accidentally" created by nature. For example, if we were to say that the constant chaos of our early earth created an "accidental" condition for life to evolve, then our "god" would be the earth itself. Why define a god as a living entity? What defines god? If god is spiritual, then what difference would that make with something like the planet earth?
2) The "evolution" argument is invalid in my opinion in that it disproves there exists a god. If anything, it further proofs that there is a god. Why would a god create each creature differently? If I were to make a clay statue, I would use clay from a common pool of clay, instead of buying new ones each day or for the different parts of the statue. Same thing with the creatures of this earth. It would make more sense for a god to use a common pool of information to create the creatures, rather than create each creature differently and by itself. Creating a uniformed law for creatures would make more sense than to create creatures that differ in both structure and make up.
3) Most people argue that without religion, wars would never occur and thus millions of lives would be saved. I find this argument to be both offensive and idiotic. For one, if you were a leader of something, wouldn't you give into what everyone believed in order to gain favor? Wouldn't it make more sense to use what everyone holds as ideals in order to fuel your agenda? For example, look at children playing a game of war. One child is always the leader, and if that child wants to remain leader what does he say to the other children? Usually something like, "tomorrow you can play leader, but today I will be." Everyone agrees - thus the ideal of the group is held together with the false belief that tomorrow someone else will get to be leader. Of course, after a while of realizing the ideal isn't upheld, the children would crush the leader and thus reform would happen. The same has occurred in most wars based on religion. Most people realize that suddenly the war means nothing, the leaders corrupted, and that they were just using religion to uphold their own gains. If everyone liked shoes, then war would be based on shoes. Religion is powerful in that it hold beliefs; in the hands of corrupted, those beliefs can be used against the people.