Reincarnation is a return cycle. If you have not found an exit leading you to paradise, you must go back. Just like on a freeway, if you cannot find the exit, you must return in order to find it. This is reincarnation.
The theory of reincarnation should not be taught, because we don't have an entity to reincarnate. What reincarnates perhaps are these clinging tendencies to the information we got, whether bad or good, and then that clinging tendency will go and find one instrument after another to satisfy our longing that we did not complete from our previous so-called birth. After the knowledge, the Wisdom or the God-Self that resides in this body leaves this temple, he or she will pass to another temple. It is like going from one church to another, we are still the same person. Actually, in the universe there is no one entity that exists. There is a mass of energy and a loving field, but sometimes it is divided into different sections. It is just like the electric current that is in the bulbs, in the wire, in the microphone in different shapes. It is in the refrigerator, a different shape again, and in the electric fan, but the inside current is the exact same thing.
The soul never reincarnates, just our habitual thinking, our desires, our attachments that reincarnate. If we know the soul, if we are enlightened, if we know the connection with the whole universe, we are not reincarnated anywhere, we are always right there. We are never born, and never die.
Actually, there is no birth. There are no souls residing anywhere. We are always free.