"Evolution is false, so god made everything."

 

"So you're saying Jesus didn't exist at all?"

 

This is a common mistake people make, and they may not realize they are doing it. That's why it's important to point these things out. This is a way of thinking where the possibilities are oversimplified and reduced to just 2 (or more) ideas, which are supposed to cover everything. Dichotomy refers to 2 options, trichotomy would be 3 and so on. The dichotomy is the most common version I have experienced.

 

In the first example above, the theist is trying to simplify the explanation for the existence of humans by saying that it must either be because of evolution, or due to god. Then by trying to discredit the evolution angle, they think they are therefor proving their favoured alternative. The problem is that they are ignoring the fact that there could be a myriad of other possible explanations, even if evolution was wrong. This is why it's called a false dichotomy. For example, humans could have been brought here by aliens, there could have been a freak accident where plants turned into some humans, or they could have been created instantly by a bizarre chemical reaction. Of course there is no evidence for any of these, but neither is there any for god. What the theist has done is to dismiss out of hand any other possible explanation, of which there can be an infinite number of. There is no justification for doing so. The real explanation may be something no one has ever thought of. Instead, they need to provide positive evidence for their position.

 

In the second example, the theist is setting up a false dichotomy where either Jesus was exactly as described in the bible, being the son of god and performing miracles, or he didn't exist at all. This is excluding the obvious third option, where Jesus did exist, but his deeds have been grossly exaggerated in the bible. They are trying to force you to one extreme or the other, ignoring all the possibilities inbetween.