2 Chronicles 13:10 But as for us, the Lord is our God, and we have not forsaken him; and the priests, which minister unto the Lord, are the sons of Aaron, and the Levites wait upon their business.
In Abijah’s speech to Jeroboam and the people of the Northern Kingdom, he accuses them of setting up their own priests to minister to their false gods, the golden calves, but we (Judah) have retained the true worship of the true God with the chosen priests and Levites. He says they have not forsaken the Lord but have remained faithful to the Lord and His prescriptions for true worship.
Now the truth may be a little different than that, for 1 Kings 15:3 says that Abijah was unfaithful to God and was a wicked king. However, the Chronicler chose to highlight the little good he did in order to show that he was still under God’s covenant promise to David. He did not forsake the Lord, as Jeroboam did. Because of his fiery speech recorded here, he was spared the immediate consequences of his sin.
The example for our learning is this: although we are sinners justly deserving God’s wrath and judgment, we are at the same time saints who have received God’s grace, favor, and blessing because of Christ. We confess our sinfulness, repent of sins, and believe in Jesus, our Forgiver and Savior, who brings us righteous before God. Jesus is my God, my Lord and Savior, and because of the gospel I will remain faithful to Him.