FearGod, you should study the case of bacteria that become resistent to antibiotics. This is a real true phenomenon and a huge problem for many diseases in many parts of the world.
Within a population of bacteria inside a person, some are more resistent to antibiotics, and some are less resistent. When that person gets sick from these bacteria, the sickness is treated with antibiotics. Let's say that 99% of the bacteria die from the antibiotics, but 1% has a natural resistence due to their genetical composition, so they survive. The next generation will have a much higher percentage of resistent bacteria. So the population has become more resistent to antibiotics.
And because many people in many countries use antibiotics way too often for diseases the body istelf could easily cure, multi-resistent bacteria cultures are popping up more often, and this is a big problem for public health.
This is evolution! This is the very process you deny is real. And this process requires natural variations in the DNA of individuals within a population.
Is multi-resistent bacteria not happening? Is it a design from a malevolent God? Or is it a natural process?
Also, did you know that we humans have been breeding dogs, cattle, horses, sheep, plants, fruits, crops etc. for millennia in order to take advantage of random variations among individuals and select those that suit our needs best? It is not natural selection, but man-made selection, but the random variation is the same.