Scripture occasionally calls the gospel by names other than "the gospel of the kingdom of God." For instance, the Bible speaks of "the gospel of Christ" and "the gospel of God" (Romans 1:1, 16).
The term "gospel of God" simply shows it originated with God. God delivered the message to earth through His servants. Peter tells us the gospel was sent from God through Jesus Christ. Notice Acts 10:36, 37:
"The word which God sent to the children of Israel, preaching peace through Jesus Christ–He is Lord of all–that word you know, which was proclaimed throughout all Judea, and began from Galilee after the baptism which John preached…"
The gospel of God is God's good news about the Kingdom of God. The gospel of Jesus Christ is the good news Jesus brought as God's messenger. All are the same gospel; all are part of the wonderful news of what God has in store for humanity.
In a similar manner, Paul sometimes used the term "my gospel" (Romans 2:16; 16:25; 2 Timothy 2:8). This does not mean the message originated with Paul, nor was it a gospel about Paul. It was a message he received directly from Jesus Christ. "…The gospel which was preached by me…came through the revelation of Jesus Christ," he said (Galatians 1:11, 12). Paul's use of the term "my gospel" is proper because he was the one who proclaimed it.
The good news is also called "the gospel of the grace of God" (Acts 20:24). From the beginning we are called by grace, justified by grace and saved by grace (Galatians 1:6, 15; Romans 3:24; Ephesians 2:8). The "gospel of grace" is another appropriate term that focuses on a different aspect of the same gospel Jesus preached: God's enormous love for us, expressed by His grace toward mankind.
This message is also called "the gospel of your salvation" (Ephesians 1:13). Since our entrance into the Kingdom of God is synonymous with our salvation, there is no conflict in these terms for the gospel. Each complements and strengthens the other.
"The gospel of peace" is also used to describe the good news (Romans 10:15; Ephesians 6:15). The Kingdom of God will bring peace to the earth an important result of our believing in and acting on the gospel of the Kingdom. Prophesying of God's Kingdom, Isaiah said, "Of the increase of His government and peace there will be no end" (Isaiah 9:7).
All these terms describe the same gospel. They simply emphasize different aspects of the same wonderful message. Jesus Christ came preaching the gospel of the Kingdom of God (Mark 1:14, 15), taught His disciples to preach the same message (Matthew 10:7) and continued to preach it when He appeared to the disciples after His crucifixion (Acts 1:3). After Jesus rose from the dead, the apostles preached the same gospel, but with the added understanding of the meaning of Christ's sacrifice and resurrection. Although the terms that describe it may vary, the message is always the same.
The glorious truth is that this whole magnificent message is one seamless gospel, and "it is the power of God to salvation for everyone who believes…" (Romans 1:16).