When someone says that they don't 'believe in evolution,' they usually don't understand what evolution is and how it works. So it's probably good to clarify a few misconceptions about that. You can start with the confusion between the fact and theory of evolution. That species change over time is an observed fact. It is observed both in the lab and in nature. The 'theory' part deals with the mechanisms of evolution, for example, natural selection as an explanation for why species change.
Also, sometimes people refer to Darwin's 1859 book as 'Origin of Species.' But the title is much longer than that, the first part of which is: 'The Origin of Species by Means of Natural Selection....' Darwin (and others) had observed that new species arose. Then he (and Alfred Wallace) suggested Natural Selection as a theory to explain the appearance of new species. So it's natural selection that is the theory, not the fact of evolution itself.
And, if you understand how evolution works, you realize that it MUST occur. It cannot be avoided.
You might find this article useful regarding teaching evolutionary processes to skeptical students.