Hinduism scriptures say moksha is liberation from cycle of birth and death, Samsara (worldly life). This aspect of spirituality can be understood if we believe in concept of soul atman, consciousness existing inside our heart. In absence of that belief we could never understand the precept of moksha salvation as detailed in Hinduism clearly.
If we believe that it was soul atman that manifested human body and not vice versa, our understanding of spiritual principles of life would become clearer. The soul atman existing inside our heart desires liberation from cycle of birth and death forever. This becomes possible when human beings indulged in spirituality to reach cosmic end of life.
Indulging in spiritual texts like Bhagavad Gita human beings finally succeed reaching stage of enlightenment, the state when in absence of dross impurities within a soul atman reaches state of absolute purity. The whole crux of spirituality, world of soul atman lay in human beings travelling spiritual path to reach the cosmic end of life, 8.4 millionth manifestation.
Every soul atman keeps rotating in cycle of birth and death as long as a single trace of dross impurity remained within. Indulging in requisite karma when human beings become a pure soul atman, the need for soul atman to manifest a body any further ceases to exist! This stage is termed liberation from Samsara worldly life forever.
Moksha primarily is a spiritual precept. To understand it clearly our belief in existence of god, existence of world of souls’ atmans was necessitated. Having reached state of enlightenment, the enlightened one finally liberates self from cycle of birth and death and enters Vaikuntha (kingdom of god) forever. Enlightenment automatically leads to moksha.
Moksha is the state when an enlightened one after leaving mortal frame gains entry into world of god, kingdom of god. State of moksha is reached only after death of mortal body, never before.