Most creationists believe that Jesus is the agent of creation in Genesis chapter 1, because of John 1:3:
"All things were made by him; and without him was not any thing made that was made."Some creationists believe that the theory of evolution is a work of the devil. See this Google search for some examples.
This means that if they are wrong about creationism and God (Jesus) used evolution as a means of creation then they are describing his works works as the work of the devil. This is blasphemy of the holy spirit, which according to most Christian fundamentalists is the unforgivable sin.