From http://www.blavatsky.net/judge/arts/RespectingReincarnation.htm

OBJECTIONS frequently raised against "Reincarnation," and that appear to those who make them to be strong, are some growing out of the emotional part of our nature. They say, "We do not wish to be some one else in another life; how can we recognize our friends and loved ones if they and we thus change our personality? The absorbing attachments we form here are such that happiness would seem impossible without those we love."

It is useless to say in reply that, if Reincarnation be the law, it can and will make no difference what we would like or dislike. So long as one is governed by his likes and dislikes, logical arguments will not dissipate objections, and, if it is coldly asserted that the beloved objects of our affection pass at death forever beyond us, no relief is afforded to the mind nor is a strictly accurate statement made. In fact, one of the miseries of conditioned existence is the apparent liability of forever losing those upon whom we place our hearts. So to meet this difficulty raised by ever present death, the christian churches have invented their heaven in which reunion is possible under a condition, the acceptance of the dogma of the Redeemer. None of their believers seem to consider that, inasmuch as constantly many of those most closely bound to us by every tie do not and never will meet the prerequisite condition, happiness in that heaven cannot be possible when we constantly are aware that those unbelievers are suffering in hell, for, enough memory being left to permit us to recognize believing friends, we cannot forget the others. Greater than ever, then, that difficulty becomes.

What are these loves? must be asked. They are either (a) a love for the mere physical body, or (b) one for the soul within. Of course in the first case, the body being disintegrated at death, it is not possible for us, nor need we wish--unless we are grossly materialistic--to see that in the other life. And personality belongs only to the body. Hence, if the soul that we do love inhabits another physical frame, it is the law--a part of the law of Reincarnation not often stated or dwelt on--that we will again, when incarnated, meet that same soul in the new tenement. We cannot, however, always recognize it. But that, the recognition or memory of those whom we knew before, is one of the very objects of our study and practice. Not only is this the law as found in ancient books, but it has been positively stated, in the history of the Theosophical Society, in a letter from an Adept addressed not many years ago to some London theosophists. In it he asked them if they imagined that they were together as incarnated beings for the first time, stated that they were not, and laid down the rule that the real affinities of soul life drew them together on earth.

To be associated against our will with those who lay upon us the claim of mother, father, brother, son, or wife from a previous life would neither be just nor necessary. Those relations, as such, grew out of physical ties alone, and souls that are alike, who really love each other, as well as those who harbor hate, are brought together in mortal bodies as now father and now son--, or otherwise.

So, then, with the doctrine of Devachan we have the answer. In that state we have with us, for all practical purposes and to suit our desire, every one whom we loved on earth: upon being reincarnated we are again with those whose souls we are naturally attracted to.

By living up to the highest and best of our convictions, for humanity and not for self, we make it possible that we shall at last recognize in some earth-life those persons whom we love, and to lose whom forever seems such a dreary and uninviting prospect.