Most Christians across the globe are celebrating Prophet Isa's (a.s.) birth today; not realizing that 1) “Jesus” was not born on this day, 2) Jesus never celebrated his birthday, and 3) there are several verses in the Bible that prohibit this pagan practice.
As Muslims we do not refer to the Bible when in debate or discussion about Isa from the Islamic perspective. We refer to verses such as Surah At Tauba v30; or Al-Maida v116-118. For the Mu'mineen, this is enough; Isa (a.s.) never claimed to be the son of God; and never told his Apostles or anyone to worship him (“I and the Father are one” is invalid).
So where did this day come from?
Pagan Practices: In ancient times the winter solstice was celebrated as the birthday of Mithras, an ancient Persian god, and of Sol Invictus, the 'unconquered' sun god. Sir James George Frazier points out in his well-researched book, The Golden Bough, that pagan practices rivaled those of the Christians because of its solemn rituals with aspirations toward obtaining moral purity and immortality. The Julian Calendar, however, celebrated the solstice on Jan. 6, the birthday of Osiris. To compensate, the Christians began incorporating these pagan practices into their religion.
The Romans recognized Dec. 25 as the Nativity of the Sun. Celebrants in those ancient times worshiped in shrines as the new, “virgin” Unconquered Sun was “born.”
The Egyptians represented this new-born sun with the image of an infant which they brought forth and exhibited to his worshippers; the Semites in the Middle East commemorated this day as the birth of the Goddess Heavenly Virgin.
Luke 2:1 states that Caesar took census of the known world, not during the winter months; Luke 2:6-8 states the shepherds watched their flocks at night, also not during the winter months. Leviticus 23:34-36 mentions the Feast of Tabernacles, during which time Joseph (a.s.) and Mary (r.a.a.) would have traveled during warmer climes.
Jesus warned his followers in Mark 7:6-9; Matthew 5:17-19; and Deuteronomy 12:30-32 of hypocrites; upholding Allah's Law and the correct worship of Allah.
Since the fourth century Christians have basically flipped the script, substituting the birth of the new “sun,” for the birth of Jesus to avoid being associated with paganism. Pope Leo The Great rebuked the belief that Christians celebrated the birth of this unconquered sun but rather celebrated this day as the nativity of Christ.
For the Mu'mineen we have the Sunnah of Rasul'Allah to follow in this Hadith: The Prophet (s.a.w.) has said: “Do not over praise me as the Christians over-praised the son of Mary. I am His slave so say: 'Allah's slave and messenger'.” [Al-Bukhari and Muslim]
As Isa (a.s.) foretold of the coming of Prophet Muhammed as the Seal of all Prophets, ask the Christian: What Would Jesus Do?