The Law is a Steppingstone - Romans 3:28, 5:1, Galatians 2:16

man is not justified by the works of the law but by faith in Jesus Christ...for by the works of the law no flesh shall be justified.

To be justified is to be guiltless, blameless or at peace with God. Belief in the law, I say the letter of the law does not justify us. Merely keeping the law is very important, but does not have power to change our hearts. Strict trust in the law is a terrestrial practice and often reflects a certain lack of devotion and consecration.

Faith on the other hand, is dynamic since it attempts to follow the personalized dictates of the Spirit. It requires courage since one cannot predict it's requirements, nor hardly write them down as a law. Sometimes we call it the spirit of the law and it represents a commitment to perfection rather than a commitment to a minimum standard of performance. But even the phrase "spirit of the law" is lacking. It only implies an understanding of higher principles behind the letter of the law.

Faith, and more specifically faith in Christ implies not only a more perfect understanding and commitment, but a turning over of our will to Him. Again, it requires trust and courage. A leap into the dark as it were. Fortunately, although the way ahead is mostly obscured, the path already trod may at times be clear. We can discover that in times past that although the way was not well lit, it was a blessed one. Thus past experiences can serve to strengthen our faith in times of present trial.

To summarize, the law represents a bare minimum, while faith is a whole different animal.