But in those days, after that tribulation, the sun will be darkened, and the moon will not give its light, and the stars will be falling from heaven, and the powers in the heavens will be shaken. And then they will see the Son of man coming in clouds with great power and glory.
The Last Judgment Portal, Gislibertus, c. 1150, St. Lazare Cathedral
You ascend the steps of a great cathedral. But when you find yourself at the portal and crain your neck to look upward, you face When you ascend the steps of a great cathedral, the image on the tympanum over the doors is usually a scene of The Last Judgment. Before entering sacred space, the church is saying, you have to know that entering, that saying yes to the mystery you are about to enter, is a matter of life and death.
Like wise, The Liturgical Year - [ that great portal to sacred time ] begins with the end of all things.