1:16,17 In these verses the apostle opens the design of the whole epistle, in which he advances a charge of sin against all flesh; declares the only method of deliverance from condemnation, by faith in the mercy of God, through Jesus Christ; and relies upon that purity of heart, thankful obedience, and sincere desires to improve in all those graces and Christian encouragements, which more than a living faith in Christ can make real. God is a just and holy God, and we are guilty sinners. There is a righteousness as brought by the Messiah, and made known in the gospel; a gracious method of acceptance, in spite of the guilt of our sins. It is the righteousness of Christ, who is God, which comes from a satisfaction of infinite value. Faith is all in all, both in the beginning and the progress of the Christian life. It is not from faith to works, as if faith put us in a state of justification, and then works kept us in it; but it is all along from faith to faith; it is faith pressing forward, and gaining the victory over unbelief.
When Paul says, "I am not ashamed of the gospel," he means that his confidence in sharing this news is not misplaced. His confidence in his covenant with God is real and will not let him down. There is no shame in declaring your allegiance to Christ because his message is good and true.
Paul had dedicated his life to sharing the gospel (Acts 9: 3-6; 2 Corinthians 12: 2-4), and he wanted to make sure the Romans knew why he was right to align himself with Jesus, and why proclaiming Jesus' message became his life's work.