Time

Even in the spiritualworld time exists. It follows mainly the same rules as time on earth. Since sharing experiences with the spiritualworld also takes "time" it may cause a time difference of several hundred years between 2 earthly lives. It's not ready jet to "detach" or "sharing" its experiences.

Thus it's not possible for an energetic-being to travel back in time. This is because they exist in time. Time is nothing but the universal law of "cause and effect". The universe provides a frame in which cause and effect can take place.

When a energetic-being would brake the law of cause and effect (for example: by changing it around), they would place themselves outside the universe. The universe although provides the conditions for existence. In this way an the energetic-being dissolves itself because it has eliminated the conditions of existing.

Unfortunately humanity isn't eternal either so the spiritual beings keep looking for new places in the universe where they can create conscious life. They explore the universe for other material beings to make aware. Such explorations aren't without risks and therefore only highly evolved energetic-beings take part in this.