[Old] So, 4th density already exists and is among us...

[Ankh]

I don't think that fully activated fourth density entities who are going to inhabit this planet exist among us yet, except as in dual activated bodies (which are completely visible to us as they look like you and I do). Ra said that early fourth density entities will have to learn how to become invisible for third density entities first:

During the fourth-density experience, due to the lack of development of fourth-density entities, the third-density planetary sphere is not useful for habitation since the early fourth-density entity will not know precisely how to maintain the illusion that fourth density cannot be seen or determined from any instrumentation available to any third density.

So before fourth density entities learn how to do that, third density will be only in potentiation:

As the green-ray cycle or the density of love and understanding begins to take shape the yellow-ray plane or Earth which you now enjoy in your dance will cease to be inhabited for some period of your space/time as the space/time necessary for fourth-density entities to learn their ability to shield their density from that of third is learned. After this period there will come a time when third density may again cycle on the yellow-ray sphere.

Those who are among us now are the so called "new breed", and are dual activated entities:

You will find a sharp increase in the number of people, as you call mind/body/spirit complexes, whose vibrational potentials include the potential for fourth-vibrational distortions. Thus, there will seem to be, shall we say, a new breed. These are those incarnating for fourth-density work.