Life After Death?

So, what if nothing happens to us after death? Or what if, regardless of the type of life we lead, we all encounter the same fate, be it reincarnation or redistribution of energy or "Heaven" or however you believe? Many religions tout being a good person in the name of salvation and eternal bliss, but they do not know if they can deliver on that promise. What if there is nothing after this? Would anyone actually be upset and say, "Pssh! After all that?? I could've just been a jerk and still gotten to Heaven?" Why can't being a good person be its own reward? Living a life of pure intention and friendship and happiness and truthfulness, without expecting a 'treat' at the end for our good behavior. Can't we just be good for the sake of being good? -Of being pleasant to be around and making the 80 or 90 years we spend here a happy time for those around us and for ourselves! Happy people are always nicer to be around and leave good memories behind for those who loved and knew them.
I noticed that every one of the professors who said they believe in God either did not know what happens to us after death or believed there to be a next level based on the life we lead while we are here. While every professor who said they did not believe in God also did not believe that anything happened to us after this life other than decomposition and whatever imprint we left on those here (which could be considered the "spirit")