Maybe you should read it again. Consider, the prophets of the Old Testament for example. Did they love the Lord or did they serve him just because they were forced?
How about John the Baptist? Did he love to spread the gospel or was it just a chore that performed. The list goes on and on. You couldn't stop Paul to stop spreading the word after his conversion. The list goes on and on.
Contrast this will the many evil leaders that chronicled in the Old Testament. Many of them did exactly what they were "obligated" to do but not one thing more. The God of the bible is not stupid - he saw through this attempt at lip service.