Romans 7, St. Paul
says, "The law is spiritual." What does that mean?If the law were physical, then it could be
satisfied by works, but since it is spiritual, no one can satisfy it unless
everything he does springs from the depths of the heart.But no one can give such a heart except the
Spirit of God, who makes the person be like the law, so that he actually
conceives a heartfelt longing for the law and henceforward does everything, not
through fear or coercion, but from a free heart.
Martin Luther (1483-1546) in Preface to the Letter of St. Paul to the Romans