II Cor. 5:17-21
Paul stated that when one becomes a Christian, he becomes a new creation. He turns away from his old life of sin and has new aims. His new purpose is to live a new life in Christ. As a new Christian, he has been reconciled to God. He then desires to lead others to be reconciled.
Jesus chose the apostles to be ambassadors on His behalf and they received their messages directly from Him. As an apostle, Paul said that he was an ambassador for Christ. He prayed through Christ for man’s reconciliation to God.
Paul reminded the Corinthians that Christ committed no sin, but suffered and paid the price as though He had sinned. In His death, He took on our sins and our punishment, but it is necessary for us to accept Him through obedience to receive that gift.