It is my simple understanding from my personal experience in my own lives, and from what I have been told by advanced life (alien life), by spirits (people I communicate with who are deceased) and by divine life (Angels) that we are not limited to one physical life.
Just as there is a "normal" life span for us, there is a normal span of time to remain "in the spirit world" between lives before we reenter physical life - a new body and life.
There is also a "normal" number of lives we can have before we move beyond this period, into another stage of existence.
We humans all have the opportunities of "a few" lives, I am told. I don't know how many is the normal, but it is not continual forever.
We always have an individual choice of lives - it does not happen randomly.
We choose what we want to do, where we want to go, and who we want to be with for our future lives with understanding of the chances, and assume the risks of our choices.
We are never alone. We always have guidance and protection available.
When our bodies die, we are still everything we are now, and have ever been (accumulated) by spirit.
There is "some" element of physicality to our spirit. Our spirits are not made of nothing, they are made of something.
Spirits of people who have died can appear in many different ways, different forms.
Shadows, sparks, misty clouds, light spots and other shapes, and their own shape they were when alive. And other ways.
Our consciousness is tangible and audible and manipulate-able energy. (Please do not assume that I fully understand this.)
Reincarnation is real, but not in the way we commonly think of it.
We don't start over spiritually with every life. We continue to learn and grow between lives as well.
We are productively active between lives in a natural way for us, just as during life.
Our souls are in a continuum, always improving and increasing in every way - knowledge, experience, ability, intelligence.
When we come back to Earth again, we bring all our gains back with us.
This is what evolves our species spiritually.
Our human spirituality transfers our contribution to physical life just by living it.
It is normal for people to live a number of lives in their own race, with their own families.
Our spirits have a line of ancestry just as our bodies do.
Our spirits have abilities and "make-up" as unique to our own races as our bodies are.
Our spirits are "born" at the evolutional point of our race, just as our bodies are.
Our spirit inherits from the spirit of our parents, and of the evolution of the race we are incarnating into.
It is not common for a spirit of one race on one world to then reincarnate into another race on another world.
When this happens, that person (spirit) has chosen to work between the worlds.
This is how some people on Earth are directly related to beings of other races.
Also the offspring of these people on Earth are related to alien life and inherit the relationship and the opportunity of contact.
When alien people try to reincarnate into such a younger race as ours, sometimes it doesn't work at all.
And sometimes the human comes out to be deformed in some way.
And the further the leap, the more difficult is success.
The further evolved, the greater the stretch.
Souls can't incarnate into a much further evolved race.
Primitive souls cannot reincarnate into highly evolved races.
We can go down, not up.
There is no reason to go up anyway.
As soul, originally, we have our first life and this makes our spirit be of that race.
I think our soul somehow "marries" into our bodies when we reincarnate, and some races are just too different.
We are evolving our own race by being in it.
We don't have to go to another race.
There are risks being human.
We get so affected by being here.
I would say it's all part of the human condition.
Even in coming here, as souls, we risk the genetics we will get.
Even environment affects us.
We pass damage to our offspring.
Nature vs Technology
What God does, God does.
But what the aliens do by technology is manual spirituality.
I think it's like when God makes life, God makes life.
But sometimes we mix the material in a dish too.
Further evolved spirits bring their abilities to our race by living in it.
The alien races don't place human spirits into further evolved alien races.
The aliens are working here and part of their work is to put certain souls into life here.
That is within their jurisdiction.
Many spirits of people are working for us from the other side.
Many souls hope to incarnate here.
People can only reincarnate to be people again.
They hope it will be better when they come.
And for their descendants and for everyone here.