Some of the highly evolved souls who have returned to your world to assist in its raising to a higher state of consciousness are androgynous. That is, they have evolved to such a state that the male-female aspects of the original soul have been returned to the union which began.
It is this high state of develolment that enables them to serve in their present capacity -- one aspect of the soul, either male or female, incarnates in flesh while the other aspect serves its flesh counterpart from the realm of spirit. This explains in part the great loneliness and longing that both aspects feel when they are so severed.
For the sake of the dimension in which the flesh aspect has incarnated, both will again be present --- but one as male and one as female, for so it must be in your world. And a sense of completeness will once again be experienced when together, for in truth they are literally One.
As ln all Creation, the attraction of positive and negative polarities exists [in the electrical sense]. Therefore, the earth aspect of this soul will innately sense this incompleteness until such time as its true opposite pole can be reunited with it.
This is being accomplished in many ways during this phase of God's plan. In some instances through the great love and longing that exists between the soul aspects, one aspect in flesh (usually female) is instrumental, indeed absolutely necessary, to allow the male spirit and awareness to incarnate* into flesh, the Host having been chosen before its physical birth. This does not mean that the Host is a nonentity. Indeed, the Host is but a lower vibrational aspect of its own Essence that shall one day manifest within.
Although both could, under certain circumstances and for a limited time, be present in one human form, this is extremely foreign to your world and would create great distress and despair in the one so embodied. We must work within the laws and conditons of the world in which we deal. Therefore in your world the Soul that is literally One must be divided to appear as male and female.
When each has balanced its own outer and inner poles, then your higher natures can manifest through the physical instruments your personas supply. Thus did Jesus the man become the male expression of the Christ nature of the soul while Mary Magdalene embodied the Christ nature's feminine Principle. And the power of the whole or Holy Spirit was expressed in flesh to one day be recognized.
For pure spirit to occupy flesh is a difficult thing indeed, and unless such is accomplished through gradual awakening and preparation of the Host, it is too great a shock to the soul aspect so entering. That is why the amount of time required. Since inception the human aspect has been enabling its own polarity exsting in spirit to draw nearer to the realm of flesh and lesson the shock somewhat.
The physical expression your mate assumes is already prearranged, but it will not matter because when the process is completed such happiness and oneness come forth as to be overwhelmng. And the higher the original soul in its development, the greater the love between the manifesting aspects and the deeper the feeling of completeness. This is understandable because the more completely balanced each one is -- the more complete the two are when together. As your Emerson states it: "There must be very two before there can be very one."
This will also explain why this great love is not always present between the two who are in truth one. The higher self is not always manifesting. This coming and going of Self shall be experienced until such time as the complete awakening is accomplished -- and this shall not be until absolutely necessary for you could exist in your world for only a short time as a fully enlightened One. The high, high vibration you would radiate and the intense sensitivity would be difficult indeed for yourselves and others. Therefore, treat with the earth aspects of one another in all gentleness, for the Christ slumbers within, awaiting only the clarion call to arise -- to come forth from its tomb of flesh.
This is the marriage made in heaven, the Holy [whole] Matrimony. The reunion of the original soul. Even slumbering in flesh, as you must of necessity be, you will sometimes glimpse the power and beauty of such a union, and this will more than compensate for the in-between periods when only the human selves are present.
So you see, as foretold, your higher selves shall indeed "walk upon the earth." Logos - the Incarnate Word -- cause hidden, effect clearly visible in your world as Two = One that Are!
*See Homecoming: Reincarnate versus Incarnate (Reflections of Light)