Note 15 at 2 Cor. 5:20: An ambassador is "a messenger and a representative. He does not act on his own authority. What he communicates is not his own opinions or demands, but simply what he has been told or commanded to say" (TNTC, p.89). It is clear from verse 20 that through the message Paul is proclaiming, Christ, and God Himself, are speaking to men. This is verified by the Greek preposition "huper" that means "in behalf of or in one's stead." God is indeed speaking His message today through the voice of men.

"Ambassadors are mentioned from the time of Moses to the Maccabean period (1 Macc. 9:70; 11:9; 14:21; 15:17). Disrespect shown to them was regarded as a serious insult to their sovereign and his people, and sometimes led to war (2 Sam. 10:4)" (Zondervan Pictorial Encyclopedia of the Bible [ZPE], Vol.1, p.126). The term is used in the New Testament when speaking of Paul and all true ministers of Christ (Eph. 6:20; 2 Cor. 5:20).

Note 16 at 2 Cor. 5:20: As one representing Christ, Paul is now entreating others to be reconciled to God. This offer is to those who are alienated (Col. 1:21), enemies (Rom. 5:10), sinners (Rom. 5:8), and those without strength to help themselves (Rom. 5:6). It is secured by God in Christ (2 Cor. 5:19), through the death of Jesus (Eph. 2:16; Col. 1:21-22), and by His blood (Eph. 2:13; Col. 1:20). When received by faith the effects are the peace of God (Rom. 5:1; Eph. 2:16-17), and open access to God (Rom. 5:2; Eph. 2:18).