Reality Is an approximate personal world view drawn from limited senses with limited processing/storage. The human brain is too limited to know an actual reality as opposed to an approximate one. Our senses are limited to certain ranges.

While realities may overlap, no two are exactly the same. Similar brain structure and input keeps the common overlap large enough to allow for communication and fellowship.

If reality is not the same for all why should god and religion be the same for all? Short answer, they cannot. However, There is nothing to stop each of us from including god in our personal reality

All that was effects all that will be. There is a tendency in the universe towards sameness or precedent. Could the future also be in the mix for an effect on the now?

Therefore what we are or become continues to affect the universe after we are gone. Could that be the basis of the concept of "the soul"? A remaining influence apart from our physical bodies. We each may have a unique pattern that continues after death. This could be created from our memory without necessarily including the details. Kind of a summation of what we have been or become.

The soul can be defined as our continued influence beyond death. Of course this could differ in different realities.