Assume us, being amazing, warrants our creation by a purposeful being.
Then wouldn't God, being even more amazing, warrant his creature by a purposeful being more powerful than God?
Therefore, this reasoning is a bit flawed.
I'm a bit confused on this topic. Obviously, evolution is not a complete theory because life had to have started somewhere, unless it always existed (even before the earth was created). Therefore, life had to have been "created" at some point. In this way, you can believe in both Creationism and Evolution.
Unless you assume that to believe in Creationism is to believe that life was created as is. However, there isn't anything in this world that humans can objectively observe as evidence for one side that directly goes against another side, since humans' lifespans are too short to observe Evolution in effect. I could believe that a pineapple created the world as is, placing fossils of common ancestors in the layers of rock. You can say "a pineapple that does that isn't a just and fair pineapple", but maybe I believe in a powerful, malevolent pineapple.