SPROUL: Justification is by faith alone. And  what does that mean? It means that there is no admixture of works in our faith that are in  any way the foundation or the basis for God’s declaring us to be just. If I had a blackboard  here and could write on it some little formulae, like your math formula 2 + 2 = 4, I would  write three of them on the board for you.

The first one would be the Roman Catholic view  of justification: Faith + works = justification.

I could write the antinomian view, the carnal  Christian view that’s so popular in our day: Faith = justification – works, so that you  can be a Christian and converted and be carnal. Christ is not the Lord of your life,  and so you believe Him as Savior, but not as Lord. And so, this idea of antinomianism is  that you can be a true believer and never have any works. Luther said, on the other hand, a  different formula: Faith = justification + works.

What does he mean? He means that if you have  true faith, you will manifest that true faith by works of obedience after you’re justified.  Now, those works, that you manifest after you are justified, contribute nothing of merit to  your justification. But if they’re not there, it proves that you don’t have what? Faith.  Because true faith will always manifest itself in works. So, Luther said it this way: “Justification  is by faith alone but not by a faith that is alone.” Saving faith will always accompany  itself with works of obedience. But again, when he talks about “alone,” it means that those  works contribute nothing to your justification.