In Hinduism both Brahman (God Almighty) and atman (soul in English) are closely related. This relationship between Brahman and atman was universal existing form beginning of time.
How do we define Brahman? In the beginning at the time of formation of cosmos it is Brahman that exploded self with a big bang to form present cosmos. Brahman is that collective entity the sum total of all souls’ atmans in cosmos in their pure state.
As detailed in Upanishads (independent spiritual treatises) if an individual grain of sand is an independent soul atman, the whole mound Brahman. If an individual piece of a puzzle is an independent soul atman, the completed puzzle Brahman.
Due to occurrence of big bang all pure souls atmans scattered all over cosmos at unimaginable speeds. In the melee, hurtling souls’ atmans gathered impurities. And finally to cleanse self of dross impurities within, regain its lost original pure prime pristine primordial form starts cosmic life journey of every soul atman when life supporting planets like mother earth evolved.
This soul atman in its entire life manifests a maximum of 8.4 million bodies to cleanse self of dross impurities within. The initial 7.3 million manifestations by a soul atman occurred in insect, plant and animal life. In the remaining 1.1 million manifestations in human form one is expected to reach state of enlightenment and finally moksha salvation.
Indulging in spirituality and reaching cosmic end of life is not a choice for human beings. It is the requirement of soul atman existing in our heart. Primarily we are a spiritual being, manifesting human body. We as a soul atman need emancipating self from cycle of birth at the earliest. Indulging in spirituality as detailed in Bhagavad Gita human beings finally reached state of self realization, god realization… 8.4 millionth manifestation, last in cosmic life cycle.
The moment an enlightened one left mortal frame, the liberated soul atman reaches state of moksha salvation, liberation from cycle of birth and death forever. This pure soul atman free of all bondages of earthly life and the solar system is now free to venture to any part of cosmos at will.
The liberated soul atman finally enters Vaikuntha (abode of God) forever. This is the stage when we can say that the pure soul atman, the independent piece of puzzle finally rejoins the completed puzzle Brahman himself!
Journey in human form for a soul atman warned the most pleasant experience, it was only in human form liberation from cycle of birth and death was possible.
Cosmic precepts like Brahman and atman become clear only by indulgence in spirituality, never religion (path of rituals). As an independent soul atman we were part of Brahman, wow!
Due to presence of ego we failed to realize our true inner essence.