I have this question for you first, If you wanted to have free will say go drink? Get high? Or lust over that girl down the block. Is that not you're choice, its you're free will to be drawn to these things?
If we didn't have free will we would be like ants, or bee's running off of pheromones just doing what is told! if you were to throw free will, the breath of life, the thing NO other animal has on this planet IT changes from Strait up Stone cold person, into a caring, emotional being.
He gives us this to make a choice to decide, if we want to live for him or live against him. It would be pretty dumb if he just made us AUTOMATICALLY worship him the second we come out of the womb. But he does give us a kind of longing a kind of pull, (some more than others) towards him. You know that "Theirs got to be more to life than this" feeling?
Basically God gave us free will for a reason, its to give you a choice to love him or leave him. He loves you that much, weather you want to leave him for the worldly things, or go to him and lay it all down.
Same thing with Satan. God made Satan, he gave him a choice, he let Satan create his kingdom. God doesn't let any thing happen he knows we cant handle. Some times we let the world/Satan get the best of us.