Lk 24:47, Jer 31:34, Isa 2:2-3, Mic 4:1-2, Mk 16:15, Acts 1:8
The Old Testament prophesied that the gospel would be preached to all nations. (Lk 24:47, Jer 31:34, Isa 2:2-3, Mic 4:1-2)
Lk 24:47 And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.
Jer 31:34 And they shall teach no more every man his neighbour, and every man his brother, saying, Know the Lord: for they shall all know me, from the least of them unto the greatest of them, saith the Lord: for I will forgive their iniquity, and I will remember their sin no more.
Isa 2:2 And it shall come to pass in the last days, that the mountain of the Lord's house shall be established in the top of the mountains, and shall be exalted above the hills; and all nations shall flow unto it. 3 And many people shall go and say, Come ye, and let us go up to the mountain of the Lord, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of the Lord from Jerusalem.
Mic 4:1 But in the last days it shall come to pass, that the mountain of the house of the Lord shall be established in the top of the mountains, and it shall be exalted above the hills; and people shall flow unto it. 2 And many nations shall come, and say, Come, and let us go up to the mountain of the Lord, and to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for the law shall go forth of Zion, and the word of the Lord from Jerusalem.
The resurrected Jesus commanded us to do this world evangelization. (Mt 28:18-20, Mk 16:15, Acts 1:8)
Mt 28:18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth. 19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: 20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.
Mk 16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature.
Acts 1:8 But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.