Genesis assumed the existence of god without any justification. Whether god exists is one of the major difference between atheist and Christian, so let the comments of this post be the forum of discussion about this issue.
For those entering comments here, please at least read Russell's teapot and theologian Alister McGrath's counter argument from wikipedia first. Please do not repeat what others have been said. If you like to support a point which other has already pointed out, you are welcome to link to the original point and extend on the argument. Thank you.