No, you are confusing microevolution with macroevolution, I do not deny that microevolution occurs, the problem is the historical extrapolation that relatively simple adaptations such as resistance to antibiotics can eventually result in huge morphological changes such as bacteria changing into amoeba type organisms, ie Macroevolution.
What mechanism(s) prevent small changes accumulating into a large change?
Such things have never been empirically observed.
Sure they have, thousands of times.
And the fossil record shows mostly organisms appearing suddenly with few or no precursors and then simply disappearing when the ecosystems change and being replaced again by fully formed organisms designed to handle the new ecosystem with no precursor forms.
Why do you think that is? Could it be due to the rarity of fossilisation?
There's no such thing as a non "fully formed" organism, although there are PLENTY of examples in the fossil record of species that exhibit 'mosaic' traits descended from their ancestral species.
No, that is only recent irrational anti-theistic development.
If by recent, you mean since the 1700s, then yes. Spinoza and Hutton both helped develop a natural philosophy that neither invoked or required the existence of deities, which was later developed into methodological naturalism, via the path of uniformitarianism.
Throughout most of the history of science most scientists were either Christians or deists and came up with some of our greatest discoveries.
Well, I disagree. I think there were plenty of non-Christian and non-deist scientists who came up with many of the greatest discoveries. I think you're giving rather short shrift to the contributions of the Greeks, Romans, Mesopotamians, Indians, Arabs, Chinese, Egyptians and other non-Western, pre-Enlightenment discoveries.
Yes, I acknowledge that the Christian west did end up making the lion's share of recent discoveries - mostly because of the development of the 'natural sciences' from the earlier traditions of 'natural philosophy'.
In addition, you could just lose the word scientist there and replace it with person (or theist) and it wouldn't change anything. The majority of discoveries were made by Christians or deists, because it was Christians or deists that were the majority of scientists.
Acknowledging a creator actually gives science a rational foundation because without Him you have no basis for believing in logic, an objective reality, and orderly laws governing an intelligible universe.
I don't. They're axiomatic assumptions inductively derived from observation of reality. However, they're also necessary.
So, I have plenty of reason to believe that reality exists, the laws of thought apply within it, and that there are no dramatic changes in the underpinnings of reality from one moment to the next. Because that's all that I experience.
However, if I supposed that the universe was produced by an entity that can create something from nothing, an entity that could create and abrogate the laws of time and space, an entity that monkeyed around directly with the fates of humans, THEN I would have no basis for believing any of the above. Because that entity could do any thing at any time for any reason. So nothing could be trusted.
Such things are absolutely necessary to even DO science.
"If the stone, for example, which fell today, were to rise again tomorrow, there would be an end of natural philosophy, our principles would fail, and we would no longer investigate the rules of nature from our observations." Hutton, J (1795).
Theory of the Earth with Proofs and Illustrations
And none of those things can come about through impersonal processes because only intelligent personal beings can use logic and create laws and intelligibility so that other intelligent personal beings can make discoveries.
This is your claim (and a lovely little tautology it is too, don't think I didn't notice). Now, kindly support it with evidence.