As I’m sure you are aware…the word Christmas is not found in the Bible.  It is interesting to note that the first recorded Christmas celebration was on December 25, 336 AD in Rome. This date was chosen because it was nine months after the Annunciation, in which the Roman Catholic church celebrates Christ’s conception.  It is acknowledged as the announcement of the Incarnation by the angel Gabriel to Mary in Luke 1:26–38. This celebration marked one of the earliest known Christian observances during the time when Christianity was prominent in the Roman Empire under Emperor Constantine.  The English word ‘Christmas’ is a shortened form of ‘Christ’s mass’.  Today, it is acknowledged by most that the birth of Christ was not in December, but probably in early fall of the year. 

The history of the celebration of Christmas is filled with pagan observances brought in to coincide with the celebration of Christ’s birth.  Beginning early in 20th century, Christmas has increasingly been a secular family holiday, observed by Christians and non-Christians alike, without any Christian thought.  It has grown into an increasingly elaborate exchange of gifts. In this secular Christmas celebration, a mythical figure named Santa Claus plays the pivotal role.  The Christmas tree is also a large part of the seasonal celebration.  Perhaps we should consider the words of the prophet in Jeremiah 10:1-5, “Hear ye the word which the LORD speaketh unto you, O house of Israel: Thus saith the LORD, Learn not the way of the heathen, and be not dismayed at the signs of heaven; for the heathen are dismayed at them. For the customs of the people are vain: for one cutteth a tree out of the forest, the work of the hands of the workman, with the axe. They deck it with silver and with gold; they fasten it with nails and with hammers, that it move not. They are upright as the palm tree, but speak not: they must needs be borne, because they cannot go. Be not afraid of them; for they cannot do evil, neither also is it in them to do good.” 

Today, many celebrate Christmas as the birth of the Lord Jesus.  What a remarkable event that took place the day that Christ was born.  On that day, “The Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.” (John 1:14).  On that day, “God was manifest in the flesh…” (1 Timothy 3:16).  On that day, “God sent forth his Son, made of a woman, made under the law, To redeem them that were under the law, that we might receive the adoption of sons.” (Galatians 4:4-5). 

Today, many godly believers choose not to celebrate a day that is not the true date of the birth of the Lord, a day that has its beginnings steeped in heathenistic practices, a day that is widely celebrated by unbelievers with ungodly behavior and greed. 

You asked about using XMAS instead of the word Christmas.  From the online Brittanica dictionary we read, “The term “Xmas” is a widely recognized abbreviation for Christmas. Its origins are deeply rooted in the Christian tradition, dating back to ancient Greek and Latin languages. The “X” in “Xmas” comes from the Greek letter Chi (Χ), which is the first letter of “Christ”. The suffix “-mas” is derived from the Old English word for Mass, thus “Xmas” essentially means “Christ’s Mass”. Contrary to popular belief, using “Xmas” is not an attempt to secularize the holiday but rather reflects its historical roots.” 

Some may be offended by the abbreviation ‘XMAS’, insisting the whole word ‘Christmas’ be used.  I would rather have us look at our own hearts before the Lord and ask Him to expose to us any sin that dwells there.  One writer wrote many years ago that it is much easier to make people militant than it is to make them spiritual.  May we desire to please the Lord in all we do at Christmas time and at all times throughout the year.  “This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success.” (Joshua 1:8)  (CC)  (704.4)