It is my understanding that the theory of evolution basically holds that mankind evolved from a lower species over numerous generations through natural selection, gene flow, genetic drift and other selective forces.
It is my understanding that the theory of creationism basically holds that mankind, the earth and everything else was created by a supreme being or god.
When people say that "god created the heavans and the earth in six days and on the seventh he rested", who can say how long one of god's days is. Why are we so egotistical as to believe that his day is the same as our's. We don't know god (Most of us who believe in god do so because we want to not because we have proof.) but if there is a god why can't his, her or it's day be a thousand or a million or even several billion of our years.
Chapter 2, verse 7 of the book of Genises states "then the LORD God formed man of dust from the ground, and breathed into his nostrils the breath of life; and man became a living being." It does not state how long this took or what form the being we call man originally took. God's image can be many things. We have no way of knowing. Additionally, although the bible is supposed to be the word of god, it was written by humans and therefore subject to human interpretation.
When we create something we start out with one thing and then add to it and alter it untill we finish and with some creations, such as a garden, we never finish adding to and altering it. Who says that god could not have started with one cell and through evolution added to it and altered it untill it became a human being. Who can say for sure that he, she or it is still not adding to and altering mankind. Who can say that god did not make us in such a way that we would continue to evolve without his, her or it's intervention. Who can say that the process is finished. Chapter 2 verse 1 of the book of Genesis states "Thus the heavens and the earth were finished, and all the host of them.". I have not found any place in the bible that states humans were finished.
It is said that "god created man in his own image". Since no one has ever seen god who can say what that image is. Who knows what humans will look like or how they will think in a thousand, ten thousand or one hundred thousand years. Maybe someday all humans will look and think exactly alike. Maybe someday all humans will merge into one being.
If there is a being powerful enough to create us then that being would be so far above us that we could not possibly understand it's thought processes or how it created or is creating us. We can not know what is intended for us or how or if things will end.
No human knows or understands everthing. No human can state beyond all doubt that there is or isn't a god. No human is infallible. Anything is possible, even the possibility that evolution and creationism are part of the same process.