There are some people who think that God is love, and that He cares for everyone. Others think that God is a big meanie, living up in the heavens, ready to destroy us if we do anything wrong. The truth encompasses both.
Nahum 1:1-8 recounts Nahum’s prophecy against the city of Nineveh, declaring that it would be destroyed. The chapter starts out by telling us that God is zealous and angry, and He is going to pour out His rage on His enemies. Some translations use the term jealous which is a character of God that some find hard to understand. God is jealous in a way that a parent would be for a child: protective of His children and His authority.
In the midst of this passage is Nahum 1:7 which tells us that God is good and will protect those who take refuge in Him. Because God is good and just, He cannot withstand evil forever, but He is merciful. He will protect His own, those who choose to repent, but He will judge those who choose to remain His enemies. God does not have a bad temper, a short fuse as it were; He is slow to anger. (Nahum 1:3, Exodus 34:6, Psalm 145:8, Joel 2:13) He is not willing that any should perish. (II Peter 3:9) He is omniscient and knows right from wrong, and He would like us all to do the right thing, but He gives us a choice. And for those of us who choose to repent, God’s goodness is the best news of all. He will protect those who put their trust in Him. That is why Nineveh had to be destroyed, because God was protecting the people of Judah from the Assyrians. The people of Judah had to endure the trial for a time, but God was on their side. He is on our side too, and the trials that we face will be only for a time. Nahum predicted both judgement and hope. Which you receive depends on your response to God.