The absolute spirit, consciousness existing in our heart is our atman on its cosmic life cycle of 8.4 million manifestations. This spirit moment in gets separated from its source Brahman, God Almighty creator of entire cosmos, it desires rejoining its source.
Of its own it cannot purify itself and needs a medium, a body to work out its karma. The moment an atman manifests a human body for the first time it keeps reminding the human form of its cosmic goal but infested with an ego human beings failed to hear promptings of this atman from within. The result, cosmic journey of atman to liberate itself from cycle of birth and death comes to a halt.
In such circumstances there was no remedy except when human beings indulging in spirituality desired reaching god. The desire to reach God finally culminates in human beings reaching end of cosmic life and the atman finally regaining its lost original pure prime pristine primordial form.
Undertaking spiritual journey is not a requirement of the manifest human form, prime reason why most human beings on mother earth shied away from indulging in spirituality. Indulgence in spirituality is necessitated if we desire becoming a Mahavira, Gautama Buddha even Jesus Christ or Prophet Mohammed at the end of spiritual journey.
The status of all enlightened souls is exactly the same. At the end of cosmic journey when human beings finally gained enlightenment, all reached its source the cosmic spirit God Almighty himself.
The spiritual journey relates to absolute spirit within, the reason why it is called journey of spirituality towards the inner self we also called spirit.
Realizing self, realizing god, realizing this spirit, gaining enlightenment all meant the same.
In fact we are the spirit that manifested human form. Due to presence of ego within we failed to realize our true identity as a spirit. Indulging in spirituality detailed in Bhagavad Gita we not only realized our true identity as a spirit but also reached the cosmic source Brahman, God Almighty.