A Scientific Theory is "an explanation or model based on observation, experimentation, and reasoning, especially one that has been tested and confirmed as a general principle helping to explain and predict natural phenomena.". As such, a theory held by the majority of the scientific community can generally be thought of "truth as it is known now". Important scientific theories include the theories of relativity, gravity, and electromagnetism.
I do not have the personal knowledge to prove evolution, and I do not claim to. Instead, I have read research, books, and articles on both sides of the question and come to what I believe to be the most logical conclusion. The argument you have is with these sources, not with me, as my knowledge and experience is not as robust as these peer reviewed studies. Arguing against me proves nothing except that I don't know everything.
However, as a sign of good faith (otherwise known as feeding the trolls, which I am notoriously bad about doing) the reasons why I "believe" in evolution:
1) There are a number of flaws in human and animal anatomy that are best explained by evolution, such as the appendix, or the plumbing design of women (such as problems of having their uterus fall out under certain circumstances)
2) There is a MASSIVE amount of genetic evidence linking all known species of animal, including particular instances where we know how/when a particular gene or chromosome evolved. For example, monkeys have an extra chromosome when compared to humans, but the genetic markers for the beginning of the chromosome have been found in one of our (the human species') chromosomes.
3) Radiometric dating and other dating methods have shown steady progress in complexity of life. Despite the occasional claims to the contrary, they have never found fossils of people hunting a T-Rex.
4) The Universe is BIG. The chances of an earthlike planet existing is good, and given enough time abiogenisis and subsequent evolution (if even remotely possible) would inevitably happen.
5) There have been actual experiments demonstrating the evolution of a trait through natural genetic variation (and some artificial selection to speed up the process a hair).
6) Lots of other stuff I have yet to learn.
Now if you'll excuse me, I have class in the morning.