Ah, this tired crap again. First things first though. Evolution is not the same thing as the theory of evolution. Stop presenting it like the same damn thing. The Phenomenon of evolution is a natural process that we can observe the same as gravity, the water cycle and countless other processes. The Theory is the explanation of that phenomenon.
See, the difference here is that the theory, the explanation of the hows and why of evolution can be given or denied a belief. The phenomenon itself is a fact and therefore can't be a belief, it either is or is not.
To compare, this is like asking if I believe in lightning. Someone might say lighting is actually gods throwing the bolts and not the scientific explanation, but only a true nutjob goes "there is no lightning!" This is why creationists are dismissed so often, as they never acknowledge the reality of the phenomenon in the first place, thus reveal the worthlessness of their position.If someone refuses to admit to reality from the start, you can't take them seriously.
ok, now that we have explained that there is two issues raised whenever someone asks "do you believe in evolution", lets address things.
Do I believe in the phenomenon? As much as I believe in gravity, water, atoms and every other aspect of reality that can be observed and tested. You know, not a belief at all so much as fact. Anyone who denies it, well, is a damned idiot who invalidates their opinion because only an idiot or a madman denies reality because they don't like it.
Do I believe the theory? Yes. I find it explains the phenomenon well, has been tested countless times and can be used to predict. It is the best explanation of the process for the phenomenon called evolution. I can see why some might disagree with the explanation for the process, instead dismissing the facts and testing for the wishful thinking of intelligent design, but honestly, I have only ever known one person to actually say "evolution happens but the theory that explains it isn't right/complete". Instead I get idiots who deny reality because it threatens their delicate delusion.
So remember people, even if you don't like what the theory describes, it doesn't fucking matter because the phenomenon is a simple fact and no amount of whining will change that, even if the explanation of why is "only a theory"