How can salvation involve real human choice when God has already made a sovereign choice?

I have a question about the Lordship controversy. In particular, volition. I've attended a lot of your services, and I've heard you mention volition a few times, and also in your Study Bible. My question is, how can volition be a part of the salvation equation if God is completely sovereign?

John:
How can human volition be a part of salvation if God is sovereign? The answer is, the sovereignty of God produces an effect through a means. Okay? And, the activating of the human will is the means. God evangelizes the world through the means of sending us to every creature. We become the means by which the Lord reaches the elect. And, there is a means by which God saves, and it is through faith, and that faith is an act of the human will--not apart from the power of God--but by means of the power of God.