For about a year before I became a Catholic, I used to worship on Sundays with one of two meetings of the Religious Society of Friends, also known as the Quakers. These days often remind me of the Quaker tradition of the Inner Light, which seemed to be their way of talking about the presence of God within, by which we are meant to discern our steps and find our awareness of God's action in the world.
This tradition often comes to mind for me during the Christmas Octave, when so many of the liturgical prayers and Scriptures we hear are built around the Johannine arrival of the Light. We hear the prologue to the Gospel of John on Christmas day, inviting us to rejoice in the "true light, which enlightens everyone," that is "coming into the world." Then during the octave we hear a lot from the letters of John, which remind us to walk in the light we have received. We who live in the northern hemisphere, for whom the physical daylight follows our theological reflection, are especially fortunate. From now until we celebrate the nativity of John the Baptist, the daylight will increase. Then, the birth of he who "must decrease" signals the loss of the daylight until we celebrate the Lord's birth once again.
Our faith tells us that the Light which is born for us at Christmas is now resurrected into the grace of our baptism and communion. God now sends us to be mirrors of the Light to one another.