Romans 10:13-15, 17
For, “Whoever will call on the name of the Lord will be saved.” How then will they call on him in whom they have not believed? How will they believe in him whom they have not heard? How will they hear without a preacher? And how will they preach unless they are sent? As it is written: “How beautiful are the feet of those who preach the Good News of peace, who bring glad tidings of good things!” So faith comes by hearing, and hearing by the word of God.