We speak of faith that is not an idle thought, but that liberates from death and produces a new life in hearts. This is the work of the Holy Spirit. This does not coexist with mortal sin. As long as faith is present, it produces good fruits. About the conversion of the wicked, or about the way of regeneration, what can be said that is simpler and clearer? Let the Scholastics, from so great a host of writers, produce a single commentary that speaks about the way of regeneration. When they speak of the habit of love, they imagine that people merit it through works. They do not teach that it is received through the Word. They teach just like the Anabaptists teach at this time. But God cannot be interacted with, God cannot be grasped, except through the Word. So justification happens through the Word, just as Paul says in Romans 1:16, "[the Gospel] is the power of God for salvation to everyone who believes." Likewise, he says in 10:17, "Faith comes from hearing." Proof can be derived even from this: faith justifies because, if justification happens only through the Word, and the Word is understood only by faith, it follows that faith justifies.
How will Christ be Mediator if we do not use Him as Mediator, if we do not hold that we are counted righteous for His sake? To believe is to trust in Christ's merits, that for His sake God is reconciled with us. (paragraphs 64-67, 69)
Condensed from CONCORDIA: THE LUTHERAN CONFESSIONS, copyright 2005,2006 by Concordia Publishing House. Used by permission. All rights reserved. To purchase a copy of CONCORDIA, call 800-325-3040.