Romans 10:14-15 — How then shall they call on Him in whom they have not believed? and how shall they believe in Him of whom they have not heard? and how shall they hear without a preacher?
And how shall they preach, except they be sent? as it is written, How beautiful are the feet of them that preach the gospel of peace, and bring glad tidings of good things!
Verse 15 quote is from Isaiah 52:7 — How beautiful upon the mountains are the feet of him that bringeth good tidings, that publisheth peace; that bringeth good tidings of good, that publisheth salvation; that saith unto Zion, Thy God reigneth!
Paul gives in the fourteenth and fifteenth verses a beautiful little discourse, to show the Jews the necessity for taking the gospel, which is intended for all, to all. If God provided a righteousness which is for all, if we know anything about it, then the obligation and responsibility for taking it to all lies upon us. In other words, world reconciliation demands world evangelization. He approaches this responsibility in reverse order, but nevertheless in a way that emphasizes the need. — Alvin J. McClain, Romans: The Gospel of God's Grace, page 191.