If I didn't screw anything up let's summ up some creationism:
God created the world some 5000 years ago (or similar relatively short period, devised from the Bible in ways unclear to me) in a state that has almost not changed since then.
Evolution is a lie, as is any history dating back more than the Bible mentions.
Since creationists believe in the creator God, they also believe He is omnipotent, capable of performing any action, any creation. Stating otherwise would be hypocrisy/heresy/blasphemy (choose most appropriate), Let's just skip that He needed to rest after working for 6 days, some of which didn't even exist yet because He hadn't created the day/night cycle yet at that point. The Catholic Church (and who knows which other churches agreed with that) already discovered that Genesis was a prayer-type tome, not a history-type one.
To those still ignorant to the directly above:
Since God is omnipotent, he is not bound by time as we know it and can create THE PAST! including creating a good few billions of years before the original creation and altering the original creation to fit in with the new prehistory..which now includes evolution.
How much chaos does that bring forth?