It is believed that the natural phenomena were worshiped in the very ancient prehistoric world. This phenomeno is called animism. After that period, humans have worshiped the animals escpesially the big ones. As we notice, our first ancestors were afraid of strength that was dangerous for them and that they didn't understood. After that period and with the progress of agriculture people used the woods as means to grow plants and domestic animals, so they started to see the Gods and they noticed that they had human bodies.