If by the term "creationism", you are referring to the belief held by a select number that insist that a literal interpretation of Genesis reveals that the earth is less than 7 thousand years old, evolution is some kind of false doctrine and that their beliefs have some kind of scientific validity... than I am forced to say that not only does it it lack merit, but it is actually dangerous.   

I say dangerous because thirty years ago when I attended a national convention of biology teachers it was quite evident that religious doctrine was causing textbooks to become "watered down" by publishers to avoid being boycotted by major book buyers. The Texas Book Depository - the one involved in the Kennedy assassination- is the central purchaser of school books in Texas. So if a Christian fundamentalist attitude runs that authority, they wield tremendous power. And trust me, they do.

Creationism is just one expression of religious zealotry... the Inquisition was another... as was the Russian purges of Jews. It may involve less violence, but it is oppressive to freedom of thought and speech.

What preceded the big bang... I have no clue, and I leave it at that.
But I do know biology, ecology and evolutionary theory, and there is no way I will accept or tolerate their attempts to deny facts and replace them with their absurd assertions.