The Eastern Orthodox and the Eastern Rite Churches within the Roman Catholic Church chose January 6. The Western Church based in Rome chose December 25, as early as AD 336. Thus, many Christians do not realize that much of the celebration of Christmas is actually of pagan origin. The Romans celebrated the Feast of the Invincible Sun on December 25. The early church fathers elected to celebrate the birth of Jesus (PBUH) on this date, although there was no particular reason to choose this one…
No one disputes that the event and all its symbols came from pagan religions; it has nothing to do with the birth or teachings of Jesus Christ. For one thing, no one knows with certainty the date of birth of Jesus Christ. "In fact, dates in almost every month in the year were suggested by reputable scholars at one time or another," notes The American Book of Days. For another, the celebration of birthdays is itself a pagan idea, never promoted by any Prophet or Book of God, including the Bible. Early Church leaders opposed it strongly. As late as 245 CE African Church father and philosopher Origen wrote that it was sinful even to contemplate observing Jesus's birthday "as though he were a King Pharaoh" (The American Book of Days).
No, Christian fundamentalists are not extending their pagan-bashing case against Halloween to include the feast of Santa, nor is this a McKibbenite screed against the commercialization of Christmas. Those quotations are from an "Islamic View on Celebrating Christmas, New Year" in Riyadh Daily. It's an interesting demonstration that, when it comes to taking the fun out of anything, Christian, Muslim and secular true believers have plenty in common.
But the article goes beyond that to argue against all forms of religious birthday observations—including Mohammed's birthday, which is popularly observed in many places. One of the biggest selling points of Islam has always been that it eschews idolatry and the worshipping of a human being—a stance that sets up paradoxes (e.g., if you believe Jesus was just a mortal, why do you also believe he will come again in the end times?) and worse, leads to melodrama (like the Great Expectations-type plot twist wherein Jesus gets swapped out at the last minute and either Judas or a Golem in Jesus' shape gets crucified in his place).
I side with Edward Gibbon in believing that religions get worse as they get more abstract, so all this posturing about who is actually the least pagan strikes me as some kind of Goon Island competition in which people strive to see who's feeblest, most nearsighted, etc. What's interesting isn't why Muslims talk about the "Defeat of Christianity at the Hands of Paganism" but why Christians don't brag about that paganism and cite it as their religion's greatest virtue. If people didn't like worshipping idols, Paula Abdul would still be out of work.