The Twin rays or Twin flames are ONE cell from Creator Source, one soul, that in the origin was divided into two polarities, to experience the incarnations and know itself, embody and discover unconditional love in a long journey through the third dimension to finally return to Source as ONE, Ascended.
Throughout many lives they were incarnated, sometimes one of them, sometimes both, but particularly in the previous incarnation to Ascension both incarnate, in two opposite polarities, as it was in its origin.
Both will have a strong spiritual awakening in this incarnation, and the meeting occurs, in one way or another.
Their souls are preparing for their next reunion and merging. Which is a process that is not easy, because all outstanding wounds they need to heal, by each one of them, will come to the surface.
They may be aware of the connection (both) or just one of them will.
Prior to that, they probably had experiences with kindred souls that will more or less prepare them with the energies of the next encounter with the true twin flame.
They are souls in service, and their meeting will have the purpose to serve to help to the rising of the planetary vibrations for the ascension of the Earth in general. The union is very important because it is part of divine plan, for their energies are strong individually, but when they become a unit, their energy is healing at its greatest and higher potential, and is expansive.
But prior to this, they must have completed the healing process, both parties, because a meeting at the moment they are not prepared, could even be detrimental to both.
At 5th dimension level (since we are all multidimensional) both are already ONE, and are part of the Guide received, by both parts, when they really listen to their hearts.