The argument goes that there is no whole, concrete “theory of creation” like there is for the “theory of evolution.”
Let’s ignore, for now, that there are large bodies of disparate work, research, data, evidence and writing for both creation and evolution.
I would like to propose a statement that should be absolutely clear, straightforward, and easily answerable via scientific rigor.
If the earth was created six-thousand years ago and all life was wiped out in a global flood then we should be able to observe evidence to such a scenario.
We should be able to make predictions about the past and present, that would result from a global flood, and then go out and observe these things.
One of the key tenets of the scientific method is making falsifiable claims – predictions. If a claim is not falsifiable — meaning that an experiment can not be performed to support or argue the claim — then the scientific method is not being followed and therefore can not be respected by the larger non-creationism community.
As it turns out, you could probably follow this process entirely on google, obtaining research, googling the research to find support or detractions, creating predictions based on claims and googling support and detractions on that, etc., etc.
There is so much data out there that may support creationism but, perhaps secular science has a point, we’re unable to point to a consolidated body of work that we can call the “theory of creation.”
A brief google returns only a handful of doubtful results. Perhaps one of the big organizations out there (I’m looking at you Answers in Genesis!) might want to put a bit of effort into creationism consolidation.