Nope. There's a
lot around to
debunk this. Here's a lengthy one that also goes into the
Mythras claimed about Christmas but also covers the Sol Invictus stuff as well.
TLDR: Sol Invictus appears to have originated LATER than Christians celebrating Christmas on Dec. 25th. Christian celebrating Christmas on Dec 25th comes rather from a Jewish and Christian tradition which basically held that Prophets and such anointed died at the same date they were concieved. The Annunciation thus Christ's conception was traditionally held to be on March 25th... add nine months to March 25th and... oh look, we're smack on December 25th.
And the classic claim about the Christmas tree and Yule logs being pagan in origin. Here's a previously linked site going over a
bunch of the myths. Here's a more
specific debunking of the Yule ties to Christmas, which goes over known Yule traditions and see how many appear as part of Christmas (protip: one tentative link of serving boar to Christmas ham and... well... that's REALLY tentative) and even goes into how the oldest references to what became known as the "Yule Log" didn't actually reference Yule but were referencing... wait for it... CHRISTMAS with no mention of Yule or "Yule Log" AT ALL. In point of fact, there's more connecting Yule to how we celebrate NEW YEARS than to how we celebrate Christmas in the west (which actually makes sense seeing how Yule was, actually a NEW YEARS feast).
As to the Christmas tree... there's actually no
evidence of pagan origins for Christmas tree, but a lot for Christian origins, and a much later origin than any other traditions, as the first records of Christmas trees did not appear until the 16th century. There's not any evidence for decorating tree and bringing them into homes in any major pagan tradition. Rather it appears to have originated from the use of Paradise Trees in Advent Plays, with people decorating the Paradise trees with treats to represent the fruit of life and fruit of knowledge. The earliest scholarship trying to claim pagan origins again goes back to the late 19th century romantics whom were TERRIBLE at all things science, but especially archeology. As I noted in the thread this spun off of, if the idea about Christianity originated in the late 19th century, disregard it, 99% of the time it's wrong and a result of purposeful misrepresentation meant to tear down Christianity and not based in actual historical fact.
Nonsense, Sol Invictus was initiated in 274 AD. The earliest known Christmas celebration was
336 AD, far later. Claiming the Sol Invictus celebration came later is blatant revisionist history and complete falsehood. Note that your sources don't remotely support the claims you're making, they're basically going "Well really Christianity started in Genesis 3:15 so wayyyy! older," coupled with "We don't have the actual records, only copies of them dating all the way back to 274, so the oldest known intact calendar is later." Incredibly weak and deceptive arguments, as expected of those trying to support untruth.
Your links have no serious facts in them, they're just saying "X is so" with no research, no backing, and a heck of a lot of reaching. I'm particularly amused by that last one, it's literally just the author ranting about how ancient pagans weren't really environmentalists as we know them today (true enough) and therefore they didn't care about trees (false) so they couldn't have been the origin of Christmas trees (even Reed Richards would call that a stretcher). "I found a website on google that supports my pre-assumed ideas" isn't actually useful data. We know straight up that German Pagans worshipped trees.
en.wikipedia.org
Even many Christian Traditions dating back centuries have connections between the German Yule and the incorporation of those pagan traditions into the Yule Log and Christmas Tree. F'rex
Saint Boniface, Apostle to Germany, is sometimes credited as creating the first Christmas tree to integrate German pagans into Christianity. The modern tree decorated with lights originates with Lutheran customs in the Rennaisance connected too... German pagan customs they integrated.
As far as conception, there's nothing biblical about saying he was conceived on March 25th, and since the bible itself establishes
quite thoroughly that Jesus wasn't born on December 25th that means there must have been
something else that pushed them to choose such a date. Perhaps a pre-existing celebration to coopt. The evidence is too overwhelming for it to be anything else, too many elements from the pre-existing celebrations from Holly to Haloes to the Yule Log and Yule Tree to Santa being identified with Odin.
None of these things are biblical, they're just "This bunch of men said this centuries later" and one simply picks which bunch of men they decide to listen to (American Puritans actually forbade Christmas due to its Pagan components). One who chooses to listen to the bible instead of men, though, will get a different message. There is no biblical Christmas tree, no sign in the bible that Jesus ever celebrated his Birthday at all in fact (and we do know they had birthdays, John the Baptist was beheaded at one, it's just that Jesus' own is conspicuously absent and every time a birthday is mentioned in the bible, it's entirely shown as negative. Almost as if God did not intend us to celebrate it).
Even if the folk traditions of Christmas were pagan in origin, practicing them today would not be pagan worship. For it to be pagan, it would have to be religious. It would have to be directed towards the pagan gods. Nobody today worships the pagan gods like yggdrasil. Nobody puts up a Christmas tree thinking that they are honoring some Norse mythological god. Folk tradition just means a tradition of the people. It does not mean that they are worshipping some pantheistic god. It just means that they brought their folk traditions with them when they became Christians.
If you really want to get technical about it, a Christmas tree is more Christian than yggdrasil. Yggdrasil is an ash tree. A Christmas tree is a cedar tree. What was Christ's temple built out of? The cedars of Lebanon. The poles of the Ark were made of cedar. The use of cedar is very specifically mentioned in the Bible.
Lolwut?
Exodus 25:12,13
12 And thou shalt cast four rings of gold for it, and put them in the four feet thereof; and two rings shall be on the one side of it, and two rings on the other side of it. 13 And thou shalt make staves of acacia wood, and overlay them with gold. 14 And thou shalt put the staves into the rings on the sides of the ark, wherewith to bear the ark.
As for the Temple, it's true cedar was used in it but stone, iron, copper, silver, and gold were also specifically mentioned, there's no reason to presume ceremonial value for every construction material. Too, Christmas trees are not traditionally cedar, most are Fir Trees and any conifer can be used.
While one can do as they wish as part of a secular holiday, it is wrong to attempt to associate it with worship of God or Jesus, as God does not accept worship that isn't rooted in Truth.
John 4:24
God is spirit, and his worshipers must worship in the Spirit and in truth."