The exiles acted as if they were seeking the Lord. But they were only going through the motions. They performed the outward actions, yet their hearts had turned away from him. They were worshiping idols, which the Lord calls detestable (deeply hateful and unclean).
It was easy for them to think that Babylon’s many military victories proved something. They could begin to believe that real power belonged to the Babylonian gods, not to the Lord.