So, in the end what is the final decision maker?
If in a believer, with a new nature, facing the temptations to sin, why does he sin and when he does is it God willing him to do so?
Moreover, Sproul is setting up a strawman to knockdown.
No one is defending the neutral theory since choices are based on desires.
The question is what the the ultimate source and thus, who bears the responsiblity for that choice, God or man?
In other words, when we sin, we must reject God's Holy Spirit, and do our own will.
Is that part of God's will for our lives, to sin?
The problem the Calvinists have is that they will not concede that man can resist God's will a resistance that God allows and does control, but nevertheless a resistance against God and foreknown by Him. (Acts.7:51)