So you behave independent of reward and punishment?no not really because there is only one type of reward but there are many ways to behave.Maybe from a child's perspective, but there's way more to it than that. You'd think if that were truly the case there'd be more than 46 out of 31,102 verses that discussed what you claim is the central theme of all religions.The bible still promises a reward from god.
The end result is always easy to define. How to achieve is always more complicated.