Romans 10:14-17
14 How then shall they call on him in whom they have not believed? and how shall they believe in him whom they have not heard? and how shall they hear without a preacher?
15 and how shall they preach, except they be sent? even as it is written, How beautiful are the feet of them that bring glad tidings of good things!
16 But they did not all hearken to the glad tidings. For Isaiah saith, Lord, who hath believed our report?
17 So belief [cometh] of hearing, and hearing by the word of Christ.