I just completed Richard Bach's book ONE. He throws out the idea that all of our lives are running at the same time in a different dimension. He visits his other lives as a kind of a guide. Telling them to really, really consider their choices before making them.
I also know of a psychic that went to her other past lives and healed them which in turn will heal her physical ailments in this life.
The possibilities are endless.
Isn't this life grand.
Love and light
Be