Neverthless, evolutionary theory is ultimately based on untestable assumptions; eg., that mutations occur randomly, as opposed to being caused by an intelligent designer.
How would you test for mutations caused by an intelligent designer? Chemistry? Paleontology? Anthropology? Physics? Biology? Microscopes? DNA? Bible? Faith?
Please, just how would you test this?
That's not an assumption. It's an inference based on observable evidence.
Besides, mutations being random is not necessarily inconsistent with them being caused by a designer. Random just means it is unpredictable given the information set available at the present. If God were causing the mutations in unpredictable ways, they would appear random to us.
"that mutations occur randomly..."
Mutations do occur randomly, as has been shown countless times in laboratory experiments.
Leave the talking points behind and get some facts. You'll be a better bug for it.
That's hardly untestable. Rather, it is a very common occurrance. Any scientist working with living cells (bacterial, yeast, animal) knows that they can and do mutate randomly and frequently, and usually interfere with the experimental plan by doing so.
Thus I presume you accept the doctrine of descent with modification from common ancestors; and we shall argue as to the mechanism of speciation (design, or random variation with natural selection). I would argue that the mutations are essentially random in nature: in the mid 20th century Fisher, Wright and Haldane worked out the mathematics and statistics of mutations and population genetics. Now we know the actual biochemical mechanisms of mutations. And they do happen at random. (Of course, selection tends to remove deleterious mutations, and favors beneficial ones; but most mutations are neutral.)
My own belief is that God created life; he intended for us to be here. And you may be right -- who can tell whether a random mutation was intended by God. But I believe God mainly did allow random mutations to create life. That is, he created a system of life that creates itself. Perhaps that is a more elegant and beautiful arrangement than for God to have simply created by fiat the various forms of life. It certainly is an arrangement more consistent with the scientific evidence.