The second important teaching of Bhagavad Gita whirled around the world of souls’ atmans. No sooner big bang occurred… all pure souls atmans got mired in impurities. To cleanse self of dross impurities within started cosmic life cycle of every soul atman. In its lifetime… every soul atman manifests a total of 8.4 million manifestations… that entailed an earthly sojourn of 96.4 million years. In 8.4 millionth manifestation… every soul atman finally reached cosmic end of life.
Out of 8.4 million manifestations by a soul atman… the initial 7.3 million manifestations occurred in insect, plant and animal life. In the remaining 1.1 million manifestations in human form… one is expected to reach stage of enlightenment (kaivalya jnana in Hinduism). From beginning to last… effort of every soul atman always remained… liberation from cycle of birth and death at the earliest. The moment a soul atman gained absolute purity… the need for soul atman to manifest further life ceased to exist.
Human beings reaching stage of enlightenment… complete eradication of dross impurities within a soul atman announced end of cosmic journey for the soul atman. The purified soul atman, moment human beings gained salvation moksha entered abode of God… kingdom of God (termed Vaikuntha in Hinduism). The purified souls atmans remained in Vaikuntha (kingdom of God) until eternity… i.e. dissolution of entire cosmos (Pralaya in Hinduism) occurred.