In verse 7, Paul states again a common claim, that his appointment as a preacher and apostle was from God. Paul was not a usurper, God had chosen him to be a vessel to the Gentiles, to teach them His precious gospel (cf. Acts 9:15-16).
Verses 5 and 6 reveal an important fact about Jesus Christ. He alone is the Mediator between God and man. This mediation is a function of His person, and His redemptive work. Jesus is here affirmed to be a man — “the Man Christ Jesus.” He is also the One through which redemption comes, “who gave Himself a ransom for all.”
When Jesus came to earth as a man, he was tempted as we are, (cf. Hebrews 4:15), “yet without sin.” In His death, payment is made for our sin, and reconciliation with God is possible. It is because of this that the Hebrew writer wrote, “Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need” (4:16).
Why do we pray, “In Jesus name”? Because it is through Jesus we have access to the Father! He is our Mediator.