“Through Him we have received grace and apostleship for obedience to the faith among all nations for His name, among whom you also are the called of Jesus Christ” (Romans 1:5-6).
The written revelation and miraculous confirmation of the gospel came through Jesus Christ and His grace.
During His incarnate ministry He graciously appointed twelve disciples to be apostles. These men accompanied Jesus from His baptism by John to the day of His ascension (Acts 1:21-22). Later, as one born out of due season (1 Corinthians 15:8), He called Saul of Tarsus to be an apostle (Galatians 1:11-17).
Upon His ascension and coronation in heaven, Jesus graciously sent the Holy Spirit, the Spirit of truth, to guide these men into all truth—the written revelation of the New Testament. The Holy Spirit was commissioned to not speak on His own but reveal the exact words Christ desired the new covenant to contain (John 16:13).
To demonstrate His approval of the apostles’ doctrine and the need to continue steadfastly in it (Acts 2:42), Jesus graciously confirmed their word through miraculous signs (Mark 16:20). The Holy Spirit’s baptism with power (Luke 24:49; Acts 1:4-5, 2:1-4) enabled the apostles to work miracles which certified their utterances and authoritative commandments as being divinely approved.
The gracious objective for this inspired revelation and miraculous confirmation of the gospel was “the obedience to the faith among all nations” (Romans 1:5). Without obedience to the once-for-all-time-delivered-to-the-saints’ faith (Jude 3), the gospel’s gracious power for salvation remains in seed form. Christ is the source of salvation to everyone who obeys Him (Hebrews 5:9).
God’s gracious offer of salvation via the gospel and its requirements of obedience to the faith to access His grace are the same for every creature in all nations. God is no respecter of persons (Romans 2:11).