During this time of "celebration" it is good to reflect, dissect, and enjoy-the Joy. Christ birth was designed thousands of years earlier, to be a big splash. The Bible from cover to cover, speaks of Christ Jesus; and with His birth marks in time - Immanuel.
The actual birth was the end of September; but the Creator of heaven and earth, legally entered time, with purpose. Christmas as a poor kid did not officially start until parents gave the OK for Nat King Cole's Christmas-album to be played. After 5 decades, my favorite song on the album has been changed.
Hark the Herald angels sing was written by Charles Wesley in 1739: It mentions Christ, has "reconciled" God and sinners. Hark = to pay close attention. To listen attentively. Herald = an official messenger, bringing news. Reconcile = to restore friendship or harmony, settle, resolve, a verb[Strong's].
The Christmas Story, is actually a Christmas-Statement. God came into time to kick Devil butt: Christ introduced the Kingdom of Heaven on earth; and the Cross provided a bridge of "Reconciliation". The hypocrites that were behind Christ-Crucified had no clue that the death sentence that Satan had, was about to be satisfied-once, for all time.
"Glad Tidings" - of the Kingdom of God. Gospel = a reward of Good[Glad] Tidings. Glad Tiding of Salvation through Christ Jesus. Jesus Christ was proved by His words, deeds, death, and resurrection - came to be called the Gospel, or Glad Tidings[The Companion Bible].