The Gospels record two important statements by Jesus about worldwide preaching of the gospel:
“And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come” (Matt. 24:14).
“And He said unto them, ‘Go ye into all the world and preach the gospel to every creature” (Mk. 16:15).
Unlike the former statement, the latter statement does not specify the preaching of the gospel of the kingdom; it only speaks of the apostles preaching the gospel. Several facts, however, make it clear that it was a command to the apostles to preach the kingdom gospel.
First, Jesus gave the Olivet Discourse (Matt. 24-25) late during His time on the earth, and He commissioned His apostles (Mk. 16:14-18) during the forty days between His resurrection and His ascension. Because the Scripture does not indicate that He gave any intervening teaching about the content of the gospel, we are justified in concluding that both references pertain to the gospel of the kingdom.
Second, Acts 1:3 highlights Jesus’ “speaking of the things pertaining to the kingdom” during the forty days between His resurrection and His ascension. Because Mark 16:15 records a key statement in seminal teaching that Jesus gave His disciples during that period, we are justified in identifying it as part of the key teaching that Jesus gave about the kingdom.
Third, Luke’s recording that Philip preached as the gospel “the things concerning the kingdom of God and the name of Jesus Christ” (Acts 8:12) makes it certain that the gospel that he received from the apostles was the kingdom gospel. The gospel that they themselves, therefore, were commanded to preach by Jesus must have been the kingdom gospel.
We thus conclude that Jesus commanded the apostles to preach the kingdom gospel to the entire world (Mk. 16:15). Furthermore, because He also taught that the end will only come after the gospel of the kingdom will have been preached in the entire world for a witness to all nations (Matt. 24:14), His followers must continue preaching that same kingdom gospel to the entire world until the end!