There is only one heaven: heaven on earth, the heaven of a well-lived life and of a well-run community and society. And there is only one way to get there: to create it ourselves.
By living as compassionate, honest, reasonable, and self-reflective people, our own lives will be better, with better friendships and greater contentment and fulfillment, and fewer enemies and problems and anxieties, than would be the case otherwise. And by cooperating with other such people, we can work together to create and sustain a compassionate, honest, reasonable, and self-reflective community and society, so that all our lives will be bettered by having such a healthy social environment in which to live.
Nothing else has been proven to work. Nothing else has been proven even to be possible.