When I was a creationist, eventually I admitted that “microevolution” could happen. I figured that changes could happen within species, but it could never turn into a new species.
The problem is, as Carl Zimmer once said, “If you accept microevolution, you get macroevolution for free.” Macroevolution is just microevolution over time. Eventually, enough genetic and/or geographical drift occurs that they become new species — organisms that no longer breed with one another.
So if you believe in microevolution: Congratulations! You’re almost there!