The second section of Edith Humphrey, Ecstasy and Intimacy, is about Light. She chooses to root her reflections in the Transfiguration, a text/event rarely discussed.
Why do you think Jesus was transfigured? Was it for Jesus — to encourage him in the face of his announcement of death — or was it for the disciples — to show them what will happen beyond the death they may face in union with the crucified one? Or was it a revelation of who Christ was/is? (OK, you can choose all or more than one, but do you have any leanings?)

“Indeed,” Edith says, “it is not we who move into the light, but the Light that searches and finds us” (81).
The Transfigurations themes are discussed in each Gospel. A very nice summation, too. She then connects this to the glory of Christ and the perichoresis of the Trinity. Perichoresis, she says, does not say it all — there is more to it than the dance idea — for one must deal with the ecstatic going out to the Other(s) and the intimate participation/reception by the Other(s). And this ecstasy and intimacy spills into all creation.
What I like about this chp is that she — as a good NT scholar — ties Transfiguration to 2 Corinthians 3-4 where we find Spirit, glory, Eikon, and transfiguration themes all tied into what happens (not only to Moses but also) to Christians. In the Spirit, the believer is transformed. This is our transfiguration.