Off-topic: I think that is impossible, because God´s existance is a Religious Catholic dogma. He exist, because he exists, and I believe that fact because of my faith. As written in "some famous catholic ancient book which has the words of God" XD "He is the alpha and omega, the beginning and the end" :D
This is actually related with what I've been saying. If you are religious then there's not a single reason not to believe in the existence of free will.
You just beat the thread
Actually, that's not true at all, and the reason is a simple and ages old dilemma: if God knows everything, then He knows already everything you will ever do, hence all your actions are predetermined and you have no free will.
Just because God knows what will happen, it does not mean we dont have free will. For example, if you have a super-ultra-computer, that can analize each event that has happened, and the events that are happening; and the interaction between one and another; it can predict that, according to the way of thinking of some person, and due to the latest events that ocurred; he will do certain action.
Free will is the capacity to decide what is the "best" course of action, during a circumstance, in order to achieve certain purpose.
Also, dont forget that God is omnipresent, omniscient, omnipotent, omnibenevolent. By being Omnipresent, he is everywhere everyTIME, he is the past present and future, and that is why I think he knows it all XD.