Two souls permanently becoming one...

[anagogy]

The point I was trying to make is that there is no need to merge with another soul because oneness is already the case, permanently.

Separation is just an appearance. Granted, it can be a very convincing appearance, but an appearance nonetheless. And to the extent you believe this, or not believe in separation, you can have conscious experiences of oneness, even in 3rd density.

Ra even alludes to this:

95.25 Ra: [...] Firstly, if there has been the pre-incarnative choice that, for instance, one shall not take life in the service of the cultural group, events shall fall in a protective manner. Secondly, if any entity is able to dwell completely in unity the only harm that may occur to it is the changing of the outward physical, yellow-ray vehicle into the more light-filled mind/body/spirit complex’s vehicle by the process of death. All other suffering and pain is as nothing to one such as this.

We may note that this perfect configuration of the mind, body, and spirit complexes, while within the third-density vehicle, is extraordinarily rare.

Ra notes that these conscious experiences of complete unity are rare. However, there is a continuum of intensity to these experiences and we are always having transient experiences of varying degrees of oneness throughout our day to day lives. That's what "love" is -- a flirting with oneness.