Ad = to
Venire = to come
So Advent is the start of the pre-Christmas period when, in remembering the first occasion that Jesus came to us, we anticipate the possibility of the second. There will be a thought for the day for each day of advent. Not a comfortable thought. That would be too easy. A thought to make us twitch and squirm and, well, think a bit.
'The person who is certain, and who claims divine warrant for his certainty, belongs now to the infancy of our species.' (Christopher Hitchens, God is not Great Atlantic 2007)