'Preacher of Righteousness' in the Bible

For John came to you as a preacher of righteousness, and ye did not believe him; but the publicans and the harlots believed him; and ye, when ye had seen it, did not afterward repent, that ye might believe him.

And spared not the old world, but saved Noah the eighth person, a preacher of righteousness, bringing in the flood upon the world of the ungodly;