In their work, they do NOT consider a supernatural explanation realistic or appropriate. Whatever their private supernatural beliefs, that may motivate them, do not make them conclude supernatural explanations in their final scientific output. Ironically, if a God of the Universe exists, this God seems to bless and reward with success those that deny the existence of the supernatural in their investigation of reality. After reading the book and making the comments above I got the bright idea of checking the internet about comments on Mr. Behe's book. There are a lot.
Science is so successful because it is a purely materialistic, human endeavor.