The starting point in understanding spirituality has to be to overlook religion. Religion is contextual. Spirituality is eternal. For example human nature is same across the world. However, language varies based on nationality, region etc. Human nature can be compared to spirituality. Laguages to religions.
Instead of defining spirituality which is not a thing, which is not a theory, which is not a phenomenon, which is a form, maybe I will be more comfortable in some attributes of spirituality.
1. Everything and everyone is connected. People, events, objects everything.
2. There is one divine and the world which comprises of name and form is differntiated expression of the Divine.
3. The Divine is ever pervasive and is present in everything - organic beings, non-organic objects and the values in them and that relate to them
4. There is a sense and meaning in the occurences and processes in the world. Trying to make sense of these is futile. But having a faith in the basis of the occurence is a strength.
5. The Divine is perfect. The differentiated expression of the Divine is not. The imperfect constantly evolves to achieve the perfection.
6. The dharma, the rules of the Divine will always prevail. Truth prevails. What prevails is the truth. Satyamevajayathe.
7. Relating to the Divine is Bliss. Being able to relate to the Divine is a process of evolution which matures with age, experience, learning, introspection, and practice.