If we are saved by Christ alone, then how does "faith alone" fit in to our salvation? This is where we have to get a little technical. When we add "alone," this is what we should say: we are saved by Jesus alone but we are justified by faith alone. You see, salvation is more than justification. There are effectual calling and regeneration and conversion prior to justification as well as adoption and sanctification and glorification after it. And as we will see later, while justification is by faith alone, sanctification is not by faith alone; it requires also our works of faith (1 Thess. 1:3)--that is, our faith working itself out in obedience to God, which our faith will do if it is genuine. Faith and its works are inseparably connected like fire and its heat. But they are not the same thing.
Faith is what indicates that the inner transformation is taking place. It shows that the Spirit of God has blown over us and given us a new birth from above, which is the beginning of that inner transformation. As such, faith has an intellectual dimension: we have to know what it is that we believe. We cannot just believe: our faith has to have an object--that which we believe: in God, or in science, or in fate, or Buddha, etc. And we have to know something about that something to actually believe it.