The Buddha was very much convinced that there was no such thing as an individual soul or Atman, and rather that there was no such thing as the self.
This was deemed an essential truth to realize in the path to enlightenment.
However, this can be easily disproved through metaphysical reasoning. To some it may be blindingly obvious in their own quest for truth, but because of the muddied waters Buddhism has created, who am I, an unliberated person, to say I have found more truth than the Buddha.
I have explained in my failure of Gautama post how I think he was indeed enlightened and liberated, but his interpretation was deformed by the cultural settings of the time.
If the Atman is indistinguishable from Brahman, than how can it exist?
This is explained in the poem "Tree of Brahman". The Atman is not the whole of Brahman, but represents and acts as the whole of Brahman.
But again, how do we know that Atman is real? What is this metaphysical reasoning I've claimed?
Life is suffering. But even the most spiritually ignorant person would go so far as to agree that suffering is what grows the soul. This is an innate knowledge all of us have, because it is the ultimate purpose of our existence.
I do not believe in Samsara in the typical sense. I've spoken on this before, there are far too many dimensions extant in Brahman for this to be the case, except for perhaps an especially unenlightened or unskilled person.
For most of us, I believe this is our very first life as a Human. If it was not, the math of population growth simply would not add up. Living out our lives is a baptism by fire by which a new soul blossoms into higher existence from nothing.
It is our very sentience that causes this phenomenon. Any being who wrestles with the question of "who am I" and "why" creates a spark in the Brahman, the very beginning of a new branch.
But for this branch to grow, it must be tempered. And so life of Maya is suffering, but indeed illusory. Only in such an illusion, in such a life of attachment and dualism can one's Atman be nourished and grown.
As such, each of our experiences are unique, and grow an Atman/Brahman of their own. And while not all may achieve enlightenment in this life, those who nourish their spirit will, upon their death, be ready for a qualified freedom from Maya.
You might consider this a sort of purgatory. A place where both the enlightened Brahman and the intermediates mingle, a dualistic place beyond Maya. This can be demonstrated by the hierarchy of the 2 illusions of our existence: First, we must overcome Maya, and the illusion of the physical world. Second, we must overcome Dualism, the idea that there is any one being more powerful than another, that any specific Gods exist other than all Atmans and the One Brahman. Other than yourself.
Thus, we see a 3 tiered cosmology emerge.
Step 1: Maya, the only place Atman can emerge. The only place Atman can begin to realize the illusion of Maya.
Step 2: "Heaven" The illusion of Maya and the knowledge of oneself is well nourished within the conscience of the Atman, but the Atman does not yet realize he is Brahman. He is still bound by duality, and this world is the one in which the Deva, Asura and deities exist within the Hindu dharma as far as I can tell.
Step 3: Non Duality: The Atman has realized his identity as Brahman and knows it to be true. He too becomes to efficient and final cause of all that exists, Indistinguishable in essence to all other liberated Atman, but still unique in the heavenly dualistic world or even in Maya if he is liberated within his life.
When one becomes Enlightened within Maya, they do not suddenly cease to exist as an individual, and this carries forth to the non dualistic world.
You are real, and you are Brahman.