I am a little curious. There is a theory that God is a creation of man. If we are to carry on with this theory, then, paradise and hell are also a creation of man. In both the bible and the holy Quran, dogs are neither mentioned for hell or paradise.Yet, through life experience dogs have proved to be more wiser than humans. For instance, detectives use the help of sniffer dogs to track criminals. But more to this dogs have come to inherit man's belongings.
If dogs have acquired such status in day to day life, what should then be said of the spiritual life?
We pretend that animals have no souls, have no feelings. Yet it doesn't take a lot of brains to see an animal suffering, in pain, grief, and much more.
If we've made up God, then we've made up everything. This existence is a product of our minds. From there it doesn't matter what heaven and hell are because we made them up too, just as we made up animals.
The outcome is in our minds, based on this idea.
Spiritual life is what we create it to be, and how we learn to understand ourselves in relation to this universe. For me, that seems to be the reality of things, independent of whether or not we believe in God. The only way to comprehend this life, is to have an awareness of ourselves and the universe and what we comprehend to be in it. Belief in God is optional because it's arguable in either direction.