Isaiah 40:9
Go on up to a high mountain, O Zion, herald of good news; lift up your voice with strength, O Jerusalem, herald of good news; lift it up, fear not; say to the cities of Judah, “Behold your God!”

How then will they call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching?
Romans 10:14