Drop a ball from a building, it falls to the ground. Mix the same 2 chemicals and you get the same reaction. The brain contains neurons which are constantly firing. This is all science. They can be proven time and time again without fail. You can replicate results repeatedly. You can't say the same for the bible.
This is a common "trick" evolutionists use to discredit creationism. Namely, they discredit creationism by definition, not because it can't provide a perfectly reasonable explanation for observed phenomenon in nature. You see, the vast majority of evolutionists are atheists. And the way they've defined science and the way they utilize the scientific method is that they require that all observable phenomena in nature have a NATURALISTIC explanation. In essence, they have excluded God
a priori based on their own definition of science. They don't even consider God a possible explanation to begin with because that would be in the realm of the "supernatural," which to them isn't possible because, well, they're atheists. Thus, creationism is discredited not on its scientific merits but because it posits a deity that they don't believe in to begin with. So when an evolutionist tells you that evolution is "fact," what he's really saying is that of all possible naturalistic explanations, evolution is all we got. But if you asked that same evolutionist to debate someone like, say, Duane Gish, he'd cower in fear because he knows damn well he couldn't win. I actually used to work with a very famous evolutionist as an undergrad, and he was frequently asked to debate Gish and some of the other guys from the creation research institute, but he always declined, stating he "knew he would lose."
All observable phenomena that evolutionists cite as "clear" evidence for evolution can be explained from a creationist standpoint. And that's the ugly secret evolutionists don't want out there. Take something like the similarity in genetic code between various species. This is commonly cited as strong evidence for evolution. And, indeed, I don't debate the fact that an evolutionary model certainly would have predicted that all living species, having descended from common ancestors, would share a good proportion of their genetic code. But this finding in no way excludes God, and it in no way disproves creationism. One could simply argue that naturally the genetic code is similar among species because God worked with a common template and made minor adjustments to create a diversity of species. Why re-invent the wheel with each new species you create?
Don't ever let an evolutionist tell you that everything is nature has to be "testable" and explained through naturalistic means. There is a lot in science which isn't testable, which in my mind almost begs for a supernatural explanation. Take your example of neurons. Yes, we can test electrical conductivity in nerves. Yes, we know about sodium channels, NA/K pumps, and all the machinery that a cell uses to produce and conduct an impulse. But those are just physical phenomena. Tell me: how in the world does a voltage potential across a neuron translate into sentience, into conscious thought? Can you devise a naturalistic explanation for that? If you ask me, I find a supernatural explanation for that MORE intellectually satisfying that a naturalistic one.