Satan exists precisely because God gave all His creatures free will and He does not force them to behave in any way. They are FREE to choose not to follow God's laws, that is, to become like Satan.
While I don't believe God forces us to act in any particular way, I believe that He created us to act the way we do, mainly because He created us, and He knows how we will act. How is someone free to act, when their act, and the results of their actions, is already known?