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: 1. *notitia* One must know the basic information (or "content") such as Christ's death and resurrection. 1. *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. 1. *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?