At any given time, there are many potential people, who would be born if the right genes were combined. However, very few are actualised. Those of us who have been actualised have three successive states: potentiality; life; death.
I think that this life was preceded by potentiality, not by previous lives, and will be followed by death, not by any future lives. Spiritual development and the mythical realms of gods and a hereafter exist only in our individual brains while we are alive. It is important to meditate between now and death because there is no other opportunity.