Control of Humanity.
Heaven and Hell were created from a multitude of reasons. It was born from fear and lack of knowledge. It was the answers that humans on a metaphysical level needed. But leaders and corrupt men saw this as a opportunity. It could be used to make the general public behave and allow them to punish those who opposed their will. These rules and guidelines made people listen. The Pope grew a immense wealth from this. To the extent of at one point being the most powerful man in Europe, if not the world. Due to all this they started crusades for power, in the name of a god whose only purpose was to gain more power. It somehow justified the slaughter and slavery of millions. Starting wars, Genocides, even racism and sexism among the people. Heaven and Hell are ideas for control. That is the Truth.