Spirituality can never be taught as everything spiritual always comes from within, the entire A to Z.
Spirituality is taking inner journey towards the spirit, consciousness existing in our heart as our soul atman. Spirituality is trying to merge with the source God Almighty, Brahman in Hinduism from where it emanated.
Ever since souls’ atmans separated from Brahman, God Almighty they desire regaining their lost original pure prime pristine primordial form at the earliest. This becomes possible when human beings instead of indulging in material pursuits of life engaged in spirituality detailed in Bhagavad Gita to become a pure soul atman forever.
In present times and also in Yester era enlightenment could be gained only by indulgence in Bhagavad Gita, the teachings of Lord Krishna to Arjuna in the battle of Mahabharata. Spirituality was all about cutting shackles of karma (worldly life) to reach cosmic end of life, 8.4 millionth manifestation when one finally liberates from cycle of birth and death forever.
How to indulge in spirituality can never be taught. The inner journey, practice of spirituality is progressed indulging in contemplation (chintan) all the time. There was no other shortcut on path of pure spirituality as religious practices (indulging in rituals) never gained anything in life. We just could not avoid indulgence in contemplation (chintan) as it was the only path to reaching god.
Spirituality also can never be taught in schools. The most human beings could do was attend Satsanga, a meeting of like-minded spiritual people to solve queries within. A spiritual congregation like Satsanga was also temporal as the major journey is always covered all alone. A true spiritual traveler always prefers becoming an introvert of the highest order so that one could indulge in cosmic truths of life in isolation, in complete silence.
This is exactly the path followed by Maharshi Ramana, one who reached God in his lifetime.