:sigh:
6 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.
Punctuation is important. "of the letter" refers back to the new testament.
7 But if the ministration of death, written and engraven in stones, was glorious, so that the children of Israel could not stedfastly behold the face of Moses for the glory of his countenance; which glory was to be done away:
8 How shall not the ministration of the spirit be rather glorious?
Same context, referring to the spirit of the new testament.
So, what is the spirit of the new testament?
9 For if the ministration of condemnation be glory, much more doth the ministration of righteousness exceed in glory.
How did Paul minister this righteousness?
Romans 3
19 Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God.
20 Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin.
21 But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets;
22 Even the righteousness of God which is by faith of Jesus Christ unto all and upon all them that believe: for there is no difference: