How to get to heaven

I had Luke and McKenna in the car on the way to swimming when they started talking about relatives who had died. McKenna told him that you go to heaven when you die. Luke asked if your body went to heaven, and I responded, "Just your soul." So McKenna asked, "Just your head not your body?" I tried to explain, but apparently was unsuccessful, because Luke said,"Oh, your SKIN goes but the rest of you stays here."