I can't be 100% sure that no gods exist, but it's fairly obvious that all gods were invented by man, just like all other mythical creatures and fairy tales, so I can be quite comfortable in my belief that there are no gods. Even Christians believe that all other gods besides Yahweh were made up by man, but for some reason Yahweh gets a pass and special pleading.
Christian apologetics is the art of rolling a dog turd in sugar and selling it as a donut.