I'm currently working on Gerhard's volume about sin and free choice (arbitrium) and free will (voluntas). It's yet another wonderful discussion of an intricate theological topic, and once again it will serve as a needed remedy to the confusions of our own day.

For example, there is a tendency among confessional Lutherans today to get confused about free will and free choice. You might even catch a confessional Lutheran saying that "we don't have free will." But if "we" are baptized, we must certainly do! In fact, even unbaptized people have free will (voluntas) because by definition the will is free. It is the choice (arbitrium) of fallen man that is servile. And if you are baptized, even your choice is now free, though, of course, in great weakness. Here's Gerhard:

(II) Neither does the question concern the state of the reborn and renewed person: as to how the powers of free choice have been established in him, for we confess that the person who has been reborn and renewed through the Holy Spirit has free will toward spiritual good, in fact, a will freed from slavery to sin by the power of the Holy Spirit. Yet in this life this freedom is far from the perfect freedom of the life to come, as shall be explained in greater detail a little later. 

+HRC