Stay out from under the tree...
Sin entered into the world under the tree of the knowledge of good and evil.
Sin was then conquered upon a tree where our Saviour died a horrific death on our behalf. With this said, why would anyone spend any time at all prostrate under a pagan tree? We should be on our faces praising our Lord Jesus Christ for dying for our sins, not groveling for material things. He came to die once for our sins and He will be coming again, perhaps soon.
Hopefully He will not find us under a tree again when He comes the second time.
Let us not get carried away with vain traditions while trying to disguise them as Christian.
God spoke through the prophet Haggai that one cannot take something that is unclean and call it clean just because they want to think it is. We are also told to prove all things and to abstain from all appearances of evil.
We are told to not compromise with the world.
Let us hold fast to that which is good and stay on the old paths.
There is a good reason why there was absolutely no mention of celebrating Christmas in the first three hundred years after Christ ascended up into heaven. They knew that it was something that they should not be doing... But...the doubter will argue...why would most of all professing Christians celebrate it if it were not ok? Great question, what does the Bible say about it? Silence comes those who diligently search the scriptures for this answer.
In logic, it is a fallacy to plead to the majority as a factual proof. In the Bible it was always the "few there be that find it" and the "remnant". The majority is not always right, especially from a Biblical perspective and especially when it comes to spiritual truths. Lets dig into some key scriptures. The best way to maintain contextual integrity though is to read the Bible in it's entirety and then you will get a clear picture of what is the correct answer on this issue.
And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat: But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die. Genesis 2:16-17
And unto Adam he said, Because thou hast hearkened unto the voice of thy wife, and hast eaten of the tree, of which I commanded thee, saying, Thou shalt not eat of it: cursed is the ground for thy sake; in sorrow shalt thou eat of it all the days of thy life; Genesis 3:17 KJV
Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree: Galatians 3:13 KJV
I will praise thee: for thou hast heard me, and art become my salvation. The stone which the builders refused is become the head stone of the corner. This is the LORD'S doing; it is marvellous in our eyes. This is the day which the LORD hath made; we will rejoice and be glad in it. Psalm 118:21-24 So Christ was once offered to bear the sins of many; and unto them that look for him shall he appear the second time without sin unto salvation. Hebrews 9:28 For I have received of the Lord that which also I delivered unto you, That the Lord Jesus the same night in which he was betrayed took bread:  And when he had given thanks, he brake it , and said, Take, eat: this is my body, which is broken for you: this do in remembrance of me.  After the same manner also he took the cup, when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it , in remembrance of me.  For as often as ye eat this bread, and drink this cup, ye do shew the Lord's death till he come. 1 Corinthians 11:23-26 KJV Thus saith the LORD of hosts; Ask now the priests concerning the law, saying, If one bear holy flesh in the skirt of his garment, and with his skirt do touch bread, or pottage, or wine, or oil, or any meat, shall it be holy? And the priests answered and said, No. Then said Haggai, If one that is unclean by a dead body touch any of these, shall it be unclean? And the priests answered and said, It shall be unclean. Then answered Haggai, and said, So is this people, and so is this nation before me, saith the LORD; and so is every work of their hands; and that which they offer there is unclean. Haggai 2:11-14
Prove all things; hold fast that which is good. Abstain from all appearance of evil. 1 Thessalonians 5:21-22
Proving what is acceptable unto the Lord. And have no fellowship with the unfruitful works of darkness, but rather reprove them. Ephesians 5:10-11
I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service. And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God. Romans 12:1-2
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. Jeremiah 10:3-5 KJV
Most try to defend the above scripture (Jeremiah 10:3-5) as being not about a Christmas tree and I agree but it is about much more, including the Christmas tree. Idols come in all forms and even ideas. The context though is really about not doing the vain customs of the heathen. This falls in line with much of the Bible where it constantly warns the children of God to not do as the heathen do.
If you are participating in a tradition in ways that even the heathen do then you should seriously pray and search the scriptures to see if it is something you should be doing.
It is a fearful thing to fall into the hands of the living God. Hebrews 10:31
Ye adulterers and adulteresses, know ye not that the friendship of the world is enmity with God? whosoever therefore will be a friend of the world is the enemy of God. James 4:4