And your point was?
One can observe evolution--new traits, improved existing traits, natural selection, speciation, etc.
One can observe the distinct lines of evidence linking species we know for a fact to be related (dogs and wolves, cats and wild cats).
One can use those exact same lines of evidence to say other species, like humans and chimps, are closely related as well. In the end, all of them are.
One can make extremely specific, testable predictions on homology percentages between any two species, vestigial DNA, biographic distribution of life, transitional fossils, and other fundamentally different sets of data. No other model except common descent with modification is able to successfully predict these things, although they can be accomodated with ad hoc rationalizations, much like anything else you could observe in support of this theory. However, this also leads the other hypotheses to have 0 explanatory value and be totally pseudoscientific.
Of course, there is the human factor to add. The mental situation of the human in question can influence the reaction to any amount of evidence you can ever present. If they have already decided that the only evidence that will convince them is a time-lapse set of clear orbital photographs from the Precambrian to the present showing in minute detail every stage of evolution... you get the picture. Some will continue believing no matter the evidence, even if the stars spelled themselves out to read 'you bozos, I used evolution to make you!'
Similarly, if people had theological reasons to believe germs did not cause disease, but spirits did, no amount of evidence would convince some of them. They would use the exact same denial methods fundamentalists use against evolution--"you only have statistical links between bacteria and disease--show me a germ directly causing symptoms'. No scientist will be able to meet the challenge, because even with observation we can only infer and overwhelmingly corroborate that the germ is, in fact, the cause, and not something else.
The observations of germs causing disease and evolution producing the diversity of life are both as 'proven' as anything gets in science, and neither are fairy tales--except to people who have a pre-set agenda which requires them to reject the hypothesis out of hand before even attempting to understand it.
