The transitional plane serves essentially four purposes:
1 The transitional plane is the plane of the earthbound spirits, and as such, is NOT itself a part of the mainstream sequence of the spiritual world. It’s just the staging ground for the mainstream spiritual world. Only when a soul leaves the transitional plane can it settle-in and evolve.
2. It is on the transitional plane that souls awaken into the world of Spirit and are generally met by friends and relatives who then usher them to a more permanent home, usually within the various levels in the planes of illusion where they can continue their spiritual development. It was this function that prompted Myers to call his “Hades” a resting place.
3. The transitional plane is the only plane on which both positive and negative influences can interact with the material earth, and with each other. Spirits from the Summerlands can visit the transitional plane without too much difficulty. Spirits from the Summerlands who descend voluntarily to the transitional plane are said to be “in visitation”. These spirits visit the earth plane for various reasons. For higher spirits it is mostly to comfort their loved ones, act as guides and influence people to make good decisions. Some act as missionaries to help ignorant earthbound souls. Some higher spirits come back to the transitional plane in order to be near their old homes or the places that hold good memories for them. Lower spirits from some of the Winterlands may also return to the transitional plane, but the reasons for their return are less benign. In addition, it is more difficult for these less evolved souls to rise to a higher plane because of their lower vibration rate and energy levels.
In other words, the transitional plane contains many different types of spirits, some essentially good, most confused and unaware that they are no longer living. Each has its own agenda. It is a bit like a city street in a rough part of town where you will find mostly the homeless, the mentally ill, the drug and alcohol addicted, drug dealers and petty criminals, along with the occasional serial murderer. You will also find a slew of missionaries, a few solid citizens going to and from work and many higher spirits who have returned simply to re-experience the earthly locations that remind them of the best years of their lives.
4. The transitional plane serves as a hard floor standing between positivity and negativity. It serves as a barrier between positive and negative spirits. It is the firewall between the heavens and the hells. The transitional plane is just a staging ground for the mainstream spiritual realm, and spirits are not SUPPOSED to remain there. Ideally, they should all cross over into the mainstream sequence and progress either up or down to the spiritual level they are suited for. But the decision to cross over into the mainstream is entirely voluntary and a matter of free will.