Strange it was that some felt that the Apostle Paul needed a letter of commendation either to or from them. As Paul had been instrumental in forming this assembly, the saints themselves were living letters of commendation, Paul's epistle to all men.
A letter of commendation for every one, teacher or an elder or any of the saints, might be necessary at some time or other, if the person were not known or perhaps the gift was unknown.
I know of nothing in Scripture where a brother is sent out into gospel work or teaching with a letter from an assembly. He may be commended by an assembly but not sent. Commendation after a person has proved himself is a common practice. Servants are sent out by the Lord and are responsible for their ministry to Him alone.
The commendation of Paul was written on the hearts of the saints, not on tables of stone but in fleshy tables of the heart, "not with ink, but with the Spirit of the living God."
Paul's ministry in regard to the new covenant was the ministration of righteousness and of the Spirit rather than the law, and it was not of the letter but of the Holy Spirit. "The letter killeth, but the Spirit giveth life." The law was engraved in stone, but the new covenant was written on the heart.
What liberty the gospel gives to the heart, not a letter of "thou shalt or thou shalt not," but of grace.
Paul did not feel sufficient of himself to carry such a wonderful free gospel of grace, but his sufficiency was of God.
A contrast was shown between the glory of the first covenant, the law, in which the children of Israel could not behold the face of Moses when he came down from the mount, for the glory of his face, which glory is past, and the ministration of the Spirit which exceeds in glory, for the ministration of righteousness excels.
Moses put a veil over his face, not the first time he came down from the mount, but the second time when he had heard the Lord proclaimed merciful and gracious. The people fell under the letter even in that part of the law which was a testimony of things to be spoken afterward.
Paul's ministry was the ministry of righteousness and of the Spirit, not requiring righteousness but bringing it. The Holy Spirit could come down to dwell in man because of what the work of Christ has done, and we were made the righteousness of God in Christ. But the minds of the children of Israel were blinded even unto this day in which Christ has taken the veil away.
We have been brought into the place of the Spirit.
"Now the Lord is that Spirit: and where the Spirit of the Lord is, there is liberty." The Lord did not, like Moses, go up to make atonement; He made atonement before He went up.
Now beholding the glory with affection and with intelligence, taking delight in it, we "are changed into the same image from glory to glory," even by the power of the Holy Ghost, Who enables us to realize and to enjoy these things.
When Israel shall turn to the Lord, the veil shall be taken away. "The things that remain" are the subject the gospel treats of, not the ministry which announces it (chap. 3:11).