Malachi ~ “My [God's] Messenger”
Authorship
Likely Malachi (see 1:1). We do not have any other biographical details given about Malachi in the Bible which, combined with Malachi's generic name, has led some scholars to argue that Malachi is not the name of the prophet, but simply a description of a prophet as "My [God's] messenger". While this is possible, none of the other prophets are written anonymously and, without further evidence, I hold to the simplest explanation that Malachi is a proper name.
Date and Context
Given the fact that the issues being addressed in Malachi are very similar to those addressed in Nehemiah, it is likely these two were contemporaries. It is safe to say that Malachi was written between 435 - 430 BC. According to most scholars, this makes Malachi the last book in the Old Testament Canon.
Theme(s)
God is not Done with His People. In the book of Malachi, we find God's chosen people back in their homeland after the exile, but still sinning and rejecting God. In the book of Malachi, there are many calls to repent and return to God, but we also see that God has not given up on His people and will take action to save those who still fear Him. In this, we see God's patience, mercy, and grace clearly demonstrated.
God Must be Worshiped on His Terms. This is a theme throughout the entire Bible, but it becomes a critical point in the book of Malachi. The 'dialog' portions of Malachi make it clear that Israel was not concerned with worshiping God in the way that He designated and chose. They wanted to worship in a way that was most convenient for them. In fact, God goes so far as to say that He wishes there was someone who would "shut the gates" of the newly built Temple "that you might not uselessly kindle fire on My altar!" (1:10). God is to be worshiped on His terms, as He defines them and not according to our own agendas/convenience.
Outline
0. Introduction [1:1]
I. Israel's Wrongs Against God [1:2-14]
A. Israel Doesn't Recognize God's Love [1:2-5]
B. Israel Doesn't Recognize God's Authority and Majesty [1:6-14]
III. A Commandment for the Priests: Bring People Back to God! [2:1-9]
IV. Israel's Wrongs Against Men (and God) [2:10-17]
A. The people of Israel have married foreign women [2:10-12]
B. The people of Israel have divorced their wives [2:13-17]
V. God's Coming Judgement [3:1-6]
VI. A Call to Return [3:7-18]
A. The call [3:7]
B. A practical way to return: tithe [3:8-12]
C. The sad state of the people: testing God (in the negative sense) [3:13-15]
D. The hope of those who fear God: becoming God's own possession [3:16-18]
VII. Closing Warning/Admonition [4]
A. Judgement for some, Restoration for others [4:1-3]
B. A reminder that the promises of the law (especially Deuteronomy) are still in play [4:4]
C. 'Elijah' the prophet is promised [4:5-6]
- This is John the Baptist (Luke 1:17 and Matthew 17:10-13)
Observations/Notes
Note the use of the word "messenger" (and similar forms) throughout the book (2:7 and 3:1).
Beware of anyone who tries to apply Malachi 3:8-12 directly to Christians. This passage was not written to Christians, nor do we have the promises detailed in this passage.
This book should be read along with Nehemiah as both books are post-exile and address many of the same issues.