Commentators explain that Abijam's heart was 'not perfect' because his devotion was divided. He publicly postured as a champion for God's temple against Jeroboam, yet he privately continued his father's idolatrous practices. Scholars note this meant he likely worshipped the Lord as one god among many, rather than the one true God. This serves as a powerful warning against the hypocrisy of outward religious acts that mask a heart not fully surrendered to God alone.