Mr 1:5

Mr 1:5 And there went out unto him all the land of Judaea, and they of Jerusalem, and were all baptized of him in the river of Jordan, confessing their sin

the land of Judaea, and they of Jerusalem:

Though Jerusalem is the very naval of Judea, this is not redundant. When there are two things together they represent two aspects of the same thing. I could be said that there were two types of people who came, but it is more proper to say that those who came had two natures. Judea, (of Judah) יהוד has a hieroglyphic meaning suggesting that they were people who did not obey God; they were sinners. This is highlighted by the use of the word 'land' suggesting the earthly nature of those who sinned. 'Jerusalem' means 'teaching of peace'. Their spiritual nature was a desire for peace with God. Their repentance also had two natures: an earthly nature of physical baptism, and a spiritual nature of confession.

effective preaching

Following the prophecy of Mal 3:1 that there would be a forerunner, Malachi also says that he will be effective in his preaching.

Mal 3:3 And he shall sit [as] a refiner and purifier of silver: and he shall purify the sons of Levi, and purge them as gold and silver, that they may offer unto the LORD an offering in righteousness.