preacher; evangelist
Refers to a person who delivers sermons, especially in a Christian context, but can also be used more broadly for a moralizing speaker.
He is famous as a preacher at the church.
That preacher's talks always resonate with me.
Compound of 説教 (sermon, preaching) and 師 (master, teacher). The exact historical derivation is uncertain, but the word follows a common pattern for titles of specialists.