Martin Luther's Definition of Faith

 An excerpt from "An Introduction to St. Paul's Letter to the Romans,"

Luther's German Bible of 1522
by Martin Luther, 1483-1546
Translated by Rev. Robert E. Smith
 from DR. MARTIN LUTHER'S VERMISCHTE DEUTSCHE SCHRIFTEN.
 Johann K. Irmischer, ed. Vol. 63
 (Erlangen: Heyder and Zimmer, 1854), pp.124-125. [EA 63:124-125] August 1994

            Faith is not what some people think it is. Their human dream
       is a delusion. Because they observe that faith is not followed by
       good works or a better life, they fall into error, even though they
       speak and hear much about faith. ``Faith is not enough,'' they
       say, ``You must do good works, you must be pious to be saved.''
       They think that, when you hear the gospel, you start working,
       creating by your own strength a thankful heart which says, ``I
       believe.'' That is what they think true faith is. But, because
       this is a human idea, a dream, the heart never learns anything
       from it, so it does nothing and reform doesn't come from this
       `faith,' either.

            Instead, faith is God's work in us, that changes us and gives
       new birth from God. (John 1:13). It kills the Old Adam and makes us
       completely different people. It changes our hearts, our spirits,
       our thoughts and all our powers. It brings the Holy Spirit with
       it. Yes, it is a living, creative, active and powerful thing, this
       faith. Faith cannot help doing good works constantly. It doesn't
       stop to ask if good works ought to be done, but before anyone
       asks, it already has done them and continues to do them without
       ceasing.  Anyone who does not do good works in this manner is an
       unbeliever.  He stumbles around and looks for faith and good
       works, even though he does not know what faith or good works are.
       Yet he gossips and chatters about faith and good works with many
       words.

            Faith is a living, bold trust in God's grace, so certain of
       God's favor that it would risk death a thousand times trusting in it.
       Such confidence and knowledge of God's grace makes you happy,
       joyful and bold in your relationship to God and all creatures. The
       Holy Spirit makes this happen through faith. Because of it, you
       freely, willingly and joyfully do good to everyone, serve
       everyone, suffer all kinds of things, love and praise the God who
       has shown you such grace. Thus, it is just as impossible to
       separate faith and works as it is to separate heat and light from
       fire! Therefore, watch out for your own false ideas and guard
       against good-for-nothing gossips, who think they're smart enough
       to define faith and works, but really are the greatest of fools.
       Ask God to work faith in you, or you will remain forever without
       faith, no matter what you wish, say or can do.