My disbelief of evolution is logical, actually. If we acam from monkeys, why are the monkeys alive today not humans? And why is there nothing in between monkey and human? It's a stupid idea.
Evolution doesn't automatically kill species once a new species comes from it. Sometimes that happens because the new species uses similar survival tactics and space and are a bit better at it, and sometimes the new one is worse and just dies out (possibly spawning some new variations before extinction). Evolution happens by chance genetic mutation, so if the mutated ape just had mutant babies, which then had mutant babies and so forth to spawn a new species, the "original" apes (which of course are just one more step in a great tree going all the way up from basically strands of molecules) are still existing and doing their thing. Maybe they die, maybe they don't. We have gorillas, we have chimps, we have humans. The stuff we don't have, you probably haven't heard of... because they're extinct, ya know?
Evolution doesn't have a purpose; there is no goal. It just happens. There are and were things between monkeys and humans. Heck, I don't even know what you mean by "monkey". The hominoid superfamily has many branches. Some primates split away from our path earlier than others.
It is not a stupid idea. Go, like, learn something before spouting off meaningless and unfounded arguments under the guise of "logic".