Spirituality is most properly defined as a quest for another world. This suggests, as a reasonable man would think, that the prophets experienced intuitions which transformed them from within.
Then they went about to pass down their teachings to others. They translated their ideas into concrete symbols, something that could be more easily related to our world. Yet, the common-place folk figured that it is not the intuitions that hold transforming power, but the concrete objects and symbols the prophets allude to. Deification of scripture is the case in point. That is, how we think that every single word in the bible is divinely inspired. Or how we think there is something sacred about the wine and bread that we eat. Or how Jesus literally rose from the dead.
This is where our spirituality turns into superstition, we worship not God but our ink and paper, and whatever notions befitted the prejudices of the prophets who taught us our religion. The biggest threat to spirituality is the Judeo-Christian anthropomorphic notion of God. God is best thought of as the greatest possible good. Yet with the Judeo-Christian religious tradition it has been reduced to no more than a powerful person. As we see in our Old Testament, such a person is far from all good, and therefore the original notion of 'God' has been lost. What is abstract to the point of ineffability, which is exactly what our great prophets experienced cannot be instantiated--it cannot be made concrete as easily as they'd have us believe. Therefore the very idea of the greatest possible good in the world becoming a person is absurd.
This is another example of our spirituality degenerating into fables.