What we see is not always what is really there. Or rather, what is see is often only a small part, and the least important part. Every now and then our vision is expanded and we can see the invisible. There is a natural dynamic of this sort, and also a supernatural one. By God's grace the veil is occasionally removed and the phenomena do what they are supposed to do: mediate the nouminous. The rest of the time the phenomena are ambigious; they both reveal the deep, the invisible and hide it. We can cooperate the sharpening of our vision by cultivating virtue in prayer. This allows us to more clearly see the full truth underneath our sensible experience--although never perpetually in this life. Even those that are approaching mystical union must experience the dark night of the soul--the dessication of all spiritual phenomena, in order to focus on God in himself, lest they become attached the the creature, the phenomena.
This brings up the theological debate between the hesychasts and western theology. Is the phenomenon of the Light of Tabor a creature? In classic Palamism it is not--rather, it is the uncreated divine energies. So, one may seek them and become attached to them because it is the same as seeking God and becoming attached to Him. In wester theology, as far as I know, the light of Tabor is still a creature, although it mediates knowledge of the divinity of Christ.