Yes, powerful enough to have made a plan for all of mankind.
You haven't explained though, how, if God knows we are going to do something, we could do anything different? If one cannot do differently than that which is already known, then where is the real choice?
Because the Bible teaches that God died for the whole world and wants all men to be saved. This could not be the case if only certain ones are predestined to be saved. Therefore, we must have a choice.