I would start by clarifying the debate as being between theist and atheists rather than between creationists and atheists since there are many theists who accept evolution (the Catholic Church now). I could argue that any theist is also a defacto creationist since, even if they believe God used evolution to guide the development of life, they still see God as the ultimate source of life and its "creation". It should also be clear that evolution does not attempt to explain the origin of life but only the changes in organisms which were/are already living. Abiogenesis is the study of how life arose from nonlife.There could be a debate between Bible literalist and evolutionists but this would have a different emphasis.
It is simpler to just debate a universe with God as opposed to one without. The universe looks just as one would expect if it arose without intellegent guidence in its harsh, empty, uncaring, and cold nuetral randomness. For me, the universe makes more sense without God because of the harsh cruelty prevailent in the environments where all living things (we know of) struggle to survive everyday. In essence, there cannot be a loving, rational, intelligent being who would create such a cruel and chaotic universe.
A traditional christian concept of a biblical god is the hardest to defend due to the Bible's own contradictions, illogical structure, incoherent narrative, impossible timelines, and ever shifting personas of its god. So it would be easier to argue for a Diest god. I find the concept of a Diest god quite useless however, since it is unreachable and unconcerned with the goings on in its universe. In any case, God in any form remains invisible and silent in the realm of modern objective reality so the sciencific method cannot be used to directly study It. It is also not scientific to disprove God but rather evidence needs to be presented which proves a god exists. The Bible and its stories can be studied using the scientific method since so much of its narritive occurs in the natural world which should provide lots of physical evidence we can debate about.
In short, as long as religious concepts operate in a realm of faith in the unseen, unheard, and super natural it is out of the reach of science which is based upon evidence found in the natural, seeable, physical universe. This is why a debate about God is so difficult since we cannot agree upon the parameters of acceptable evidence. "Because an old book says so" is not acceptable evidence to those who live by the principles of empirical science.