'Nations' in the Bible

Behold, we go up to Jerusalem, and the Son of man shall be delivered up to the chief priests and to the scribes, and they shall condemn him to death, and shall deliver him up to the nations:

But Jesus having called them to him, says to them, Ye know that those who are esteemed to rule over the nations exercise lordship over them; and their great men exercise authority over them;

And he taught saying to them, Is it not written, My house shall be called a house of prayer for all the nations? but ye have made it a den of robbers.

and the gospel must first be preached to all the nations.