Psalms 98:3
He hath remembered his mercy and his truth toward the house of Israel: all the ends of the earth have seen the salvation of our God. He hath remembered his mercy and his truth toward the house of Israel: all the ends of the earth have seen the salvation of our God.
God's salvation is to be seen by all the earth, to its very ends. This universal sight takes place as people receive the gospel for themselves. That reception comes through holding meetings and doing missionary work in the cities.