Paul here articulates his important distinction between the "spirit" and the "letter" of the Law. It is part of a general dualistic view that places the "spirit" in opposition to qualities associated with the Jewish observance of the law, that is, observance of the "letter": meaningless ritualism (following the "letter of the law") and concrete literalism (physical circumcision). Thus, even when Jews do follow what they believe to be the Law, they are not doing God's will, because they fail to grasp the spirit of the Law.