God is not fooled by good behavior that springs from a hard heart. Obeying Him with an unwilling spirit may achieve His purpose, but we lose the joy of our reward.
From Jonah 4:9-11: “But God said to Jonah, ‘Is it right for you to be angry about the bush?’ And he said, ‘Yes, angry enough to die.’ Then the Lord said, ‘You are concerned about the bush, for which you did not labor and which you did not grow; it came into being in a night and perished in a night. And should I not be concerned about Nineveh, that great city, in which there are more than a hundred and twenty thousand persons who do not know their right hand from their left and also many animals?'”