The theory of rebirth is almost as ancient as thought itself and its origin is unknown. We may according to our prepossessions accept it as the fruit of ancient psychological experience always renewable and verifiable and therefore true or dismiss it as a philosophical dogma and ingenious speculation; but in either case the doctrine, even as it is in all appearance well-nigh as old as human thought itself, is likely also to endure as long as human beings continue to think.
Rebirth is for the modern mind no more than a speculation and a theory; it has never been proved by the methods of modern science or to the satisfaction of the new critical mind formed by a scientific culture. Neither has it been disproved; for modern science knows nothing about a before-life or an after-life for the human soul, knows nothing indeed about a soul at all, nor can know; its province stops with the flesh and brain and nerve, the embryo and its formation and development. Neither has modern criticism any apparatus by which the truth or untruth of rebirth can be established. In fact, modern criticism, with all its pretensions to searching investigation and scrupulous certainty, is no very efficient truth-finder. Outside the sphere of the immediate physical it is almost helpless.
It is good at discovering data, but except where the data themselves bear on the surface their own conclusion, it has no means of being rightly sure of the generalizations it announces from them so confidently in one generation destroys in the next. It has no means of finding out with surety the truth or untruth of a doubtful historical assertion; after a century of dispute it has not even been able to tell us yes or no, whether Jesus Christ ever existed. How then shall it deal with such a matter as this of rebirth which is stuff of psychology and must be settled rather by psychological than physical evidence?
According to the article, Eating is Rebirth: A report by Pavel Somov; Each meal is the beginning of a metabolic rebirth. The physical you that you currently are is about to die as you replace yourself with a new you that you are about to create with the help of what you are eating.
According to the other article I read, Rebirth Without Metaphysics in Buddhist Philosophy: A report by V. Hughes; The concept of rebirth can be described in a useful and productive way without relying on metaphysics. Rebirth as it relates to the not-self, and to impermanence can become part of our daily practice of Buddhism. Faith is accepted in many Buddhist traditions because of the concept of rebirth as described in Buddhist Philosophy: A Historical Perspective, David J. Kalupahana. it is stated there that "The process of rebirth is explained as the combining of the two factors, consciousness (vinnana) and the psychophysical personality (namarupa). The psychophysical personality referred to here is the foetus formed in the mother's womb and which represents the beginning of a new life span. Consciousness surviving from the past is said to become infused in this new personality, and thus a continuity is maintained between the two lives."
The peculiarity with having Earth lives within the cycles of reincarnation is that the newly-incarnating baby on Earth has no memory of past lives. To account for this fact it is necessary to accept that human consciousness is binary in form and not a unitary phenomenon.
At death of the physical body, if the consciousness sojourns into higher planes of consciousness (such as heaven), then the ego transposes nearly intact, with only negative aspects of its consciousness being reduced. The ego does not take the sorrow and pain of its life with it to heaven. Instead, any positive attitudes and traits of character that were created by the sorrow and pain are taken with it. The negative aspects are ‘put on hold’ till the consciousness is born again on earth, when they are added to the infant's subconscious mind.
Now I realize that this happens often just to varying degrees each moment. There is the death of one self and the rebirth of another. This a dramatic example, but one that I bet has happened to many others.
It is consciousness being "infused in this new personality". It just isn't in a new body; it's in a new version of the self. There is "death of the old" and there is "continuity" it is just in the same mind-body. The not-self is impermanent with the potential for positive change. Each experience, each moment causes change in that self. There is the opportunity in each moment for rebirth into a new self. It is up to us to realize this, and with that realization take the responsibility to make that a more positive, more engaged self.