Well, there is the basic philosophical argument that runs like this. Assume the creationist postulate that anything demonstrating complexity must have been designed. Further, that the designer is more complex than what s/he designs. We run up against a dead end when we get to God. To have designed the universe, God must be more complex than anything in the universe. To be so complex, God requires an even more complex designer. In other words, who created God?
The creationist may respond that s/he just assumes that God exists sufficiently in and of himself. To which I respond, why can't the universe exist sufficiently in and of itself? My theory, that the universe itself fulfills the "God-function" is more economical than the creationists'. [an error occurred while processing this directive]