Mandatory Morality?

Often Christians propose the idea that atheist have no morality since we do not have a religion to tell us how to govern our lives. Are you telling us that the goodness of your heart does not come from your hearts and how you live but from the mandated precepts of the bible? Do you do nice things for your neighbor because it feels good or because you have to? Doesn't it feel good to do a good deed because you want to rather than it being something you have to or something you want to do to please God? How can you consider yourself human or moral if you base who you are off of mandatory morality or because some biblical scriptures based on heresy? Being forced to do something is never correct and rarely has any positive effects on a person. From what it seems it seems Christians are just going through the motions. People are who they are based on how they lived and that which they have been exposed to. Humans are social beings that connect with each other and relate to others through themselves. There are somethings that feel good and not so good. If you do it from your heart it is far more meaningful then when you do it with a hidden agenda.What do you believe?