Do we behave out of fear of punishment, or out of the...

Do we behave out of fear of punishment, or out of the demands of our heart? For me, it is the latter, as I would hope is true for all adults, thought I know from bitter experience that such is not often the case. To act in a manner designed to catapult you into heaven would seem transparent to a god, any god,for if ones heart is not in allignment with the creator of that heaven, then... what is the point?