Coming Destruction and Redemption
Malachi preaches against sin and warns of the coming Day of the Lord which for the arrogant and evildoers will be a day of destruction, but for those who fear the Lord it will be a day of sunshine and healing. Interestingly, Malachi identifies the sins of apathy and halfhearted devotion as particularly serious sins. Offering to God what is second hand, holding back on offering our selves, and taking institutions like marriage and the family as easily to discard are some examples of what he preached against. But even the sin of being halfhearted can be repented of once we fear God, that is, trust God and His Word.