Are Paul's new revelations of the law or of the Spirit?
Paul's new revelations are not of the law but of the Spirit. The letter refers to the Law of Moses, which can only condemn and kill, having no life-giving power. By contrast, the Spirit gives life, and grace is epitomized by the Word and the Holy Spirit's work.
Les explains that Paul distinguishes law and grace, and verse 6 describes believers as able ministers of the New Testament, not of the letter. When Paul speaks of the letter, he means the Law of Moses. Paul's new revelations are not of the law but of the Spirit, because the letter kills but the Spirit gives life. The law could only condemn; it had no life-giving power. People who try to keep commandments find they only pronounce guilt. Grace, epitomized by the Word, the Spirit, and the Holy Spirit's work, gives life. Les connects this to the eternal state: no longer flesh and blood but flesh and bone, with life now in the Spirit—the same Spirit, power from on high, the Holy Spirit, who gives life.
Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.