"We begin today the season of Advent. The term 'Advent' connotes not only an arrival, but also that which is yet to come. The very word itself expresses a strange interpenetration of the present and the future, of what now exists and what is yet to come, of possession and expectation. So too, in the liturgy of Advent, the present and future of Christian salvation are mysteriously interwoven. The incarnation of the Word of God took place in the past and still continues in the present. Christ's return to judge all men and to complete his redeeming work is an event of the future, and yet is constantly on the point of coming. The expectation of this return and the memorial of his entrance into the world are both celebrated in the liturgy." - Karl Rahner SJ.
Come, Lord Jesus!
This stained glass roundel showing the advent of Christ is in the east end of the church of St Michael in Cornhill, in the City of London.