The name “Malachi” means “my messenger.” Because the term occurs in Malachi 1:1 and also in 3:1, and since the term was often used as an adjective to identify both prophets and priests as messengers of the Lord in the Old Testament (see Malachi 2:7; Haggai 1:13), and also because there is no one else named “Malachi” anywhere else in scripture, many scholars have concluded that “Malachi” is not a proper name, but merely the title that tradition has otherwise given to the author of this book. This view is supported by looking to the Septuagint (the pre-Christian Greek translation of the Old Testament), which translates the author’s name in 1:1 as “his messenger” rather than as a proper noun. However, the fact that every other Old Testament book that has a person’s name as its title features an historical person, it is most likely that Malachi was the author’s name.

Part III: Wrapping it All Up

In verse 20, he ties everything he’s discussed together and connects back to his “thesis statement” in verse 3. He once again addresses them as “dear friends.” In setting things up in v.3, he urgently encouraged his readers to “to contend for the faith that was once for all entrusted to God’s holy people.” Based on all he’s presented, he gives legs to the concept of “contending” for this vital concept by “building yourselves up in your most holy faith.” He’s adjusted the metaphor just a bit — from “contend” to “build;” from something that is adversarial to a concept that unifies. Because Jude is speaking to an audience that is steeped in the Jewish culture of the time, to speak of “building” probably suggested the concept of the construction of the Jerusalem Temple...

Part II: The Details

In verse 5, Jude digs into the details and begins to warn his listeners to avoid these teachers/leaders. First, he says that the presence of these false teachers is no surprise. (“Though you already know all this” – v.5). He presents two sets of Old Testament illustrations, with three historic examples in each set.