1 Kings 15:3

And he walked in all the sins of his father, which he had done
before him
Having such bad examples as both parents to copy after; it chiefly respects idolatrous practices, see ( 1 Kings 14:23 ) ,

and his heart was not perfect with the Lord his God;
he did profess the true God, and worshipped him, but not wholly, and only, and sincerely; he worshipped other gods besides him: and so his heart was not

as the heart of David his father;
who was a sole and sincere worshipper of God, never departed from him and his service.