Paul, a servant of Christ Jesus, called as an apostle and set apart for the gospel of God—which he promised beforehand through his prophets in the Holy Scriptures—concerning his Son, Jesus Christ our Lord, who was a descendant of David according to the flesh and was appointed to be the powerful Son of God according to the Spirit of holiness by the resurrection of the dead. Through him we have received grace and apostleship to bring about the obedience of faith for the sake of his name among all the Gentiles, including you who are also called by Jesus Christ. (Romans 1:1-7 CSB)
Paul says that he had received grace and apostleship to bring about the obedience of faith for the sake of his name among all the Gentiles. He closes his letter—many chapters later—with a similar statement: according to the command of the eternal God to advance the obedience of faith among all the Gentiles (16:26b). Thus Paul kept this purpose in mind throughout his process of writing. So what is the obedience of faith? The late John Murray suggests that in this instance, faith is describing “the subjective act of faith in response to the gospel.” Paul has evangelistic purposes. He was seeking more faithful and obedient worshipers of the one true God. Murray continues, noting that “the faith which the apostleship was intended to promote was not an evanescent act of emotion but the commitment of wholehearted devotion to Christ and to the truth of his gospel (emphasis mine).
Have you exercised the obedience of faith in response to the offer of the gospel? That is, have you trusted in Jesus Christ alone to take away your sins through his substitutionary death on the cross and to clothe you in his robe of righteousness? Paul will tell us all about that in the epistle. In the tenth chapter he puts it like this: This is the message of faith that we proclaim: If you confess with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved. One believes with the heart, resulting in righteousness, and one confesses with the mouth, resulting in salvation. For the Scripture says, Everyone who believes on him will not be put to shame, since there is no distinction between Jew and Greek, because the same Lord of all richly blesses all who call on him. For everyone who calls on the name of the Lord will be saved. Good news indeed!