'Preacher' in the Bible

Paul, a servant of Jesus Christ, an Apostle by the selection of God, given authority as a preacher of the good news,

In the day when God will be a judge of the secrets of men, as it says in the good news of which I am a preacher, through Jesus Christ.

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?