How do "Sola Fide" adherents reconcile with the three aspects of faith? Historical Protestantism (particularly in the Lutheran and Reformed traditions) have since the Magisterial Reformation held to two doctrines relating what is required of an individual for salvation.

The first is the doctrine of Sola Fide, meaning "by faith alone". This principle states that salvation is not by works of man, but by faith in Christ. In fact, not only are works insufficient to merit salvation on their own, they account for not even a portion of our salvation--it is, rather, wholly through faith in Christ.

The second doctrine was worked out by Luther and put into its present form by his collaborator and successor, Melancthon. This doctrine is simply a definition of faith, or sometimes known as the three aspects of faith--as such, it is intended to explain what is required of the "faith" for salvation "by faith alone". The doctrine has three steps:


notitia One must know the basic information (or "content") such as Christ's death and resurrection.
assensus One must agree that the basic information is correct. In other words, he/she must not only have heard that Christ died and rose again, but they must believe that he did do that.
fiducia One must trust in Christ, and rest on the knowledge that the content to which he/she assented is sufficient to save.


It is this last piece--fiducia--that I struggle with reconciling with the concept of Sola Fide. Scripture makes clear that these first two points are insufficient (James 2:19), and on the face of it, it makes sense that we must trust in Christ for our salvation.

Where I struggle is that fiducia puts faith in functional terms. This means that, although in theory, I trust in Christ for my salvation, I don't always do so in practice.

Here's an example: I'm can be a bit of a control freak, and sometimes yell at my wife in trying to assert my control. I am not loving her as I'm commanded to do so, and it stems from my pride. Although I think I trust in Christ for my salvation, my actions show that I am considering another functional 'gospel' (control) of 'salvation' and another function 'god' (myself) that will effect that 'salvation'. 

When I stop and think about it, I know that I am no god, and that my gospel is no gospel, but I do stumble and my actions reveal my heart. In fact, I would argue (and Luther has) that every sin follows such a pattern.

To come at the problem more directly, this notion of fiducia makes my faith dependent upon my works, whereas "Sola Fide" asserts that salvation is through faith and not works. How does this puzzle fit together?
The apparent contradiction stems from a misunderstanding of "works," and specifically of what Paul wrote about them.  Two passages in particular tend to cause a lot of confusion:


  Romans 10:9
  
  That if thou shalt confess with thy mouth the Lord Jesus, and shalt
  believe in thine heart that God hath raised him from the dead, thou
  shalt be saved.
  
  Ephesians 2: 8-9
  
  8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
  
  9 Not of works, lest any man should boast.


Some people have taken this to mean that salvation comes by some simple act of claiming faith and that after this, the person is saved and salvation is not affected by a person's works.  This is a very bad notion, because of what you get when you take it to its logical conclusion: "I have free license to sin because I'm saved and what I do doesn't matter!"

This isn't a hypothetical problem, either.  Here's what Richard Hill, an 18th century Wesleyan theologian, had to say on the subject:


  "God sees no sin in believers whatever sin they commit... adultery, incest and murder shall, upon the whole, make me holier on earth and merrier in heaven."


This notion is in direct contradiction to the words of the Savior, especially in the Sermon on the Mount, where he taught that not only do sinful actions put us in spiritual danger, but also sinful thoughts.  Of particular interest are his words at the conclusion of the sermon:


  Matthew 7: 21-23
  
  21 Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven.
  
  22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works?
  
  23 And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.


In verses 22 and 23, the Savior reaffirms that works of righteousness do not bring salvation if the person's heart is not in the right place and they do not truly know Jesus, but in verse 21, we see what appears to be a direct contradiction of Romans 10: 9.

James 2, which has already been quoted, states that faith without works is dead and cannot bring salvation.  Peter warned his readers about misinterpreting Paul and wresting the scriptures to their own destruction.  And John, in Revelation, makes it clear that in the resurrection we will all be judged according to our works.

So here we have Jesus himself, and also Peter, James and John, the three most trusted of his apostles, all contradicting the simplistic notion of salvation by faith alone and without works.  Faced with this, we must either condemn Paul as a heretic, or seek an alternate interpretation, and I don't particularly think Paul was a heretic.

Let's look at Romans 10: 9 first.  Remember that he was writing to Roman Christians, subject to Roman law, which wasn't all that favorable to Christianity at that point, to put it mildly.  Being willing to confess belief in Christ with your lips was no simple thing the way it is today; it was exposing yourself to persecution and possibly even death simply for the sake of your religion. That's quite a difficult thing to do, even for someone with a lot of faith!

Then we have the passage from Ephesians, where Paul states that salvation comes from faith and the grace of God, and "not of works, lest any man should boast."  Reading the context makes it clear that the works he is talking about are the works of the Law of Moses, through which Jews could find a focus for their faith and obtain salvation before it was fulfilled in Christ.  The explanation in verse 9 can be understood in that context by reading Luke 18:


  Luke 18: 9-14
  
  9 And he spake this parable unto certain which trusted in themselves that they were righteous, and despised others:
  
  10 Two men went up into the temple to pray; the one a Pharisee, and the other a publican.
  
  11 The Pharisee stood and prayed thus with himself, God, I thank thee,
  that I am not as other men are, extortioners, unjust, adulterers, or
  even as this publican.
  
  12 I fast twice in the week, I give tithes of all that I possess.
  
  13 And the publican, standing afar off, would not lift up so much as
  his eyes unto heaven, but smote upon his breast, saying, God be
  merciful to me a sinner.
  
  14 I tell you, this man went down to his house justified rather than
  the other: for every one that exalteth himself shall be abased; and he
  that humbleth himself shall be exalted.


There were those in Jewish society then, as there have always been and still are in every civilization, who boasted of their piety and outward good works and thought that what they did made them better than others.  Paul is making it clear that that attitude will score you zero points with the Lord, that even with good works and acts of righteousness, you are still a sinner and nothing you do can undo your past.  Only through God's grace can you find forgiveness for your sins.

So we see that good works do not bring salvation in and of themselves, but also that professions of faith that are not backed up with actual righteous living "is dead, being alone," as James put it.  Fiducia is a principle that bridges the gap, basically equivalent to the Savior's exhortation, "if you love me, keep my commandments," or James's explanation that we show our faith by our works.  A person with true faith will not simply sit around believing that they believe, but will go out and live the Gospel, doing good works out of love for God and love for their fellow men and striving to come always a little bit closer to fulfilling the ultimate commandment, "Be ye therefore perfect, even as your Father which is in heaven is perfect." (Matthew 5:48)