The gospel shall be preached in the whole world, “and then shall the end come.”
As Dr. Ralph Winter, of the US Center for World Missions, said famously, "We could fulfill the Great Commission within five years. But American Christians spend more on dog food than on missions."
It is just as the Scripture says: “Anyone who believes in Him will never be put to shame.” For there is no difference between Jew and Greek: The same Lord is Lord of all, and gives richly to all who call on Him, for, “Everyone who calls on the name of the Lord will be saved.” How then can they call on the One in whom they have not believed? And how can they believe in the One of whom they have not heard? And how can they hear without someone to preach? And how can they preach unless they are sent? As it is written: “How beautiful are the feet of those who bring good news!” (Romans 10:11-15)