In this daily Bible reading is the account of God preserving the lineage of King David in Judah but destroying the lineage of the evil kings in Israel. God destroyed the lineage of Jeroboam, Israel’s first king of the 10 northern tribes. Now, God was orchestrating events to destroy King Ahab’s lineage.
God destroyed Jeroboam’s line primarily because he led Israel away from God to worship idols. God was destroying Ahab’s line because Ahab allowed his wife Jezebel to kill Israel’s prophets and establish worship of the demon Baal.
I believe it was important to preserve King David’s lineage because it would lead to Jesus Christ. The Bible says that Jesus Christ will one day be King of all Israel. He will also rule the entire world for 1000 years.