It is on account of Christ that we are justified, through faith, and not on account of our faith itself.(Both from Chapter 5)
I am currently reading another book, titled. "Stop Asking Jesus into Your Heart." The premise is that we can know that we are saved, and that this knowledge is a strong basis for making our walk in Christ being stronger. (As opposed to constantly questioning our faith, and always trying to put forth a greater effort.) The author of this book equates belief with repentance, as if they are 2 sides of the same coin, like we can't have one without the other (try as we might).
I am so reminded of this as when I read this quotes. Salvation is not found in my perfection, but in Christ's perfection. He died so that I might be forgiven. And not forgiven again and again, but forgiven once and for all. This is what generates the heart that loves him. While it is faith that saves me, I am not granted salvation for my faith, but through my faith. I believe there is a difference.
If I believe that I have a need to be forgiven each time I sin, then I think I might be more likely to abuse that kind of "grace." Conversely, I also think that kind of grace also puts me more on edge, more likely to think that if I fail, I might have done so enough to "fall from grace."
Also,concerning faith, if it is my faith that saves me, I might tend to take pride in that fact. But if it is through faith that I am saved, not from myself so that I have nothing to boast of, then my tendency is to rejoice in that which was granted me, and respond not through my efforts, (Eph 2:8-10) but because of what Christ has done for me.