For more than a few centuries, early Christians didn’t even celebrate the birth of Jesus let alone Christmas.
The first recorded date of Christmas being celebrated on December 25th was in 336, during the time of the Roman Emperor Constantine.
As the first Christian Roman Emperor, Constantine was keen to spread the faith. But there was already an official Roman state festival on that date.
For the Romans, December 25th was the date of the Solstice - the day that marked the turning of winter towards longer, lighter days. In 274, the Roman Emperor Aurelian created and celebrated December 25th as Dies Natalis Solis Invicti, the birthday of the unconquered sun.
Yes, there was much reveling and feasting and drinking and gift-giving. And yes, when the Christians finally decided they wanted to mark the birth of Jesus, Constantine simply swapped out this existing pagan holiday.
Much of Christianity simply superseded and unified existing pagan believes and practices (and real estate) under a singular monotheistic religion.
All the better to spread and control everyone within the empire.
And wipe out any other means of salvation in the process.