When I was a little girl, my Sunday School teachers and church choir director made it very plain that Advent was only partly about the coming of Christmas. It was really more about Christ's second coming in glory.
Some time ago I found a blog with a posting that talks about that by referring to the Book of Revelation - also known as the Apocalypse:
Spoiler alert: if you want to know what the Apocalypse is about, I will happily summarize it for you in two words: God wins. The longer version is that no matter how mighty and oppressive earthly powers may be and no matter how dire the plight of the faithful may be, the victory is ultimately God's and those who hold fast to God and remain faithful will share in God's victory. All the rest, as they say, is commentary.
This is a book written from a pastoral perspective to people in times of persecution and affliction, a book designed to strengthen faith and give hope, a book that calls us all to repent and turn from the ways and values of the world and hold fast to God.
God wins. With the world (and the earth) facing such horrible calamities today, that's a good thing to know.