As I'm sure my readers will agree, every holiday needs to have an underlying cause (real or mythical) for the existence. Now, if it's to become a global holiday, clearly, that reason should be one that's universal, sufficiently important and highly relevant to individuals from throughout the world in order to make sure they are want to observe/celebrate it. Going further, to be on the top of the set of global holidays, the headcount of its supporters must be the maximum among that of most other possible contenders for the No. 1 spot. Nothing comes really near to Christmas in this regard, in my opinion! December Global holidays
(Note: Christianity is the greatest single religion in the world at the present time. Christians form approximately 1/3rd of the world's population, followed closely by Islam, that forms only a little over 1/5th. Contrary to popular belief, atheists & agnostics take 3rd place, accounting for only a little significantly less than 1/6th of the world's population. Arguably, but highly probable, therefore, is my claim that Christmas has the maximum amount of supporters. Also value of important intangible factors like peace, goodwill, caring, sharing etc. have to be included, before coming to one last score in case of an endeavor at comparison). (Data sources: 1. Document titled H.Res.847 of the US Govt Printing Office 2. Wikipedia 3. Wikipedia Reference'Major Religions of the World').
Let's look at Christianity now, from the perspectives of universality and global relevance just discussed above.
Irrespective of factors such as for instance being rich or poor, old or young, male or female, accepted or rejected by society etc. there's virtually no one that's not welcome to Jesus Christ! He stumbled on die for the redemption of most mankind - which means just anyone and everyone. None is left out. Therefore Christianity is universal. With the exception of Islam, it's the sole religion that wants its message of salvation to be actively proclaimed to people all around the world. Although Christianity and Islam are generally proselytizing religions, the extreme extent to which Christian missionaries go in preaching the gospel message (like suffering torture and even death) is evidence, in my own belief, of greater looking after the unreached than their Muslim counterparts. Without inviting quarrel, I'd thus like to state that I feel strongly convinced that Christianity is the most caring world religion too. At the very least, I'm sure none of my readers will contradict me if I say that it's second to none in this regard! This is quite unlike Hinduism (for example) that might accept converts to its fold; but without actively seeking them. Hence, to sum up, Christianity stands out to be truly universal plus it holds the distinction of being one of the very caring of world religions (if not THE most caring religion).
Now, let's turn to relevance. Jesus Christ is an undeniable element of history, unlike the Gods of many religions who have hardly ever really shown up on the earth. Jesus'message of salvation has been preached all round the planet even today. Isn't it clear that that message is for all? Doesn't Jesus warmly accept the poorest of poor, the unwanted, the lonely, the wretched, the sinners, the social outcasts, the returnees to a unique fold etc. whilst not ignoring others at the same time? And aren't there enough of his ardent followers everywhere who begin telling the story of their conversion, from every reason for hopelessness proven to man - existence without meaning, injustice, cruelty, oppression, exploitation, prison, addiction, strange and severe illnesses (and in a nutshell, anything that affects the human being or his soul to his ultimate destruction) to a life with sound meaning and joy in Him?
Aren't there enough of Christian institutions (hospitals, universities, orphanages, hospices and the like) that daily showcase Christ at the job in His people and light-up the meaning of the same message of salvation by their work and example? Aren't the pages of our history sprinkled everywhere with the blood of these martyred for His sake? And, aren't there his disciples throughout the world, even to this day, who'd stop at nothing (including laying down their lives) showing their love and allegiance to Him? Just how do his followers make such dramatic and visible turnarounds in life who were a number of the worst failures we ever knew before receiving Him? Christianity can be the religion credited with the initial distinction of its teaching of loving one's enemy while other religions stop at loving just one's friends. Some people might reject it, however it rejects no-one, down to the day of your respective death. Need I say more about its relevance to the entire world, even today?
On account of the important points above, the 2 prime prerequisites to being the No.1 global holiday - universality & relevance, I think are best fulfilled by Christmas. Therefore, I get this loving, grateful & well-deserved tribute to Jesus for coming up on top (once more, as everywhere else too, I think!) on the set of global holidays.