God supposedly destroyed most of the life on earth just because he was upset with people. If he wasn't in fact a devil, he would have used his godlike powers to destroy only the guilty. Then he decided to save noah and some others. Thereby nullifying his reason for the destruction to begin with. Did he stop the destruction? No.
Keep in mind we are not an ancient Chinese Dynasty and a few thousand years from the days of the Old Testament. The knowledge of both science and theology have taken great strides since then. Due to the lack of knowledge in both areas, people believed that God sent natural disasters, chose emperors and kings, and sent famines down among the people when He was unhappy with said chosen ruler.
If your understanding of natural disasters has been updated, there is no reason why your knowledge and understanding of God cannot go through that same transformation. For over two thousand years we have known that God is love, that He does not send down disasters, birth defects, etc. Just as simple observation has taught us much about science, using that same skill can teach us equally as much about God and religion.
You might be interested that Rabbis, even centuries ago, have a very different take on the story of the flood than your take on it today.