The word spirituality stems from the root word spirit that existed in all living beings as our Prana, soul atman within. None world over can deny this absolute fact of life.
If we as human beings exist, we owed it all to existence of soul atman, Prana in the body.
Spiritually we are all a cosmic traveler, a spiritual being undertaken earthly journey. Ever since the occurrence of big bang when all souls atmans in their pure form separated from its source Brahman, God Almighty himself; they got mired in impurities.
To cleanse self of dross impurities within started cosmic life cycle of every soul atman, the spirit.
Spirituality has one and only one definition. Spirits in all human beings varied as dross impurities within soul atman varied from individual to individual but the essence of all was the same.
For indulging in spirituality, for practicing spirituality to reach God in our lifetime we have to take refuge of teachings of Lord Krishna in Bhagavad Gita. In absence of teachings of Bhagavad Gita none in this world can ever reach state of enlightenment, self realization, god realization.
Spirituality is not only well-documented but how it is conducted is detailed in Bhagavad Gita.
Spirituality is all about demolishing, removing all inherent queries within us forever. As children we had many queries within us like, who I am, what is my purpose of life, my relationship with God, my relationship with world of souls atmans, does God exists, our relationship with lower forms of life, meaning of life etc.
As time passed the queries grew more and more but there were no answers at all. No matter how much people searched all over answers were not forthcoming.
It finally dawns on us that all answers to our inherent queries laid in spirituality. By undertaking spiritual journey we would not only get our answers but also succeed reaching God in our lifetime.
Reaching God means becoming a pure soul atman, regaining our lost original pure prime pristine primordial form! As long as dross impurities within soul atman remain it would keep manifesting human form after another until it reaches 8.4 millionth manifestation, last in cosmic life cycle.
Human beings who do not want to rotate in endless cycle of birth and death can indulge in spirituality as detailed in Bhagavad Gita to reach cosmic end of life.
Everything relating to spirituality is well scripted and detailed in 700 shlokas verses of Bhagavad Gita. Following teachings contained in Bhagavad Gita any human being world over belonging to any religion faith or belief can successfully travel spiritual path and reach God.
In Hinduism path to God Almighty is only one, wholehearted indulgence in spirituality, a full-time job. Those indulging half-heartedly in pastime never had a spiritual goal in life.
If we are serious about indulging in Indian spirituality then teachings of Bhagavad Gita and Upanishads (independent spiritual treatises) form the best reading material. As nothing in Bhagavad Gita or Upanishads can be understood literally, we have to indulge in contemplation (chintan) to reach the hidden underlying meaning of sacred texts.
It is only by indulgence in chintan (contemplation) we can dissolve all queries within forever.