After surveying twelve possible answers Michael Shermer ends by saying:
In the meantime, while scientists sort out the science to answer the question Why is there something instead of nothing?, in addition to reviewing these dozen answers it is also okay to say “I don’t know” and keep searching. There is no need to turn to supernatural answers just to fulfill an emotional need for explanation. Like nature, the mind abhors a vacuum, but sometimes it is better to admit ignorance than feign certainty about which one knows not. If there is one lesson that the history of science has taught us it is that it is arrogant to think that we now know enough to know that we cannot know. Science is young. Let us have the courage to admit our ignorance and to keep searching for answers to these deepest questions. Link.