Legalism fulfills the precise letter at the expense of failing to perform the intention of the Law. The following illustrates how precise obedience can entirely miss the intent of what has been asked of us:
A businessman was checking out of his hotel when he realized his briefcase was missing. "Boy," he said to the bellhop, "run up to room 1484 and see if I left my briefcase there. And hurry. I'm late leaving for the airport." The man waited anxiously. Finally, the bellhop came running up and panted, "Yes, it's still there."
Following the law is more than being incredibly precise about everything that we read in the scriptures. It is about knowing a personal God and doing what He asks for our own good.