James 4:10-12
"Humble yourselves in the sight of the Lord, and he shall lift you up.
Speak not evil one of another, brethren. He that speaketh evil of his brother, and judgeth his brother, speaketh evil of the law, and judgeth the law: but if thou judge the law, thou art not a doer of the law, but a judge.
There is one lawgiver, who is able to save and to destroy: who art thou that judgest another?"
Why does man continue to try and put other Christians under bondage of the law, where God has not? It doesn't matter what Pagans did hundreds of years ago. Would I worry that the person who invented the pew was an atheist, and so not ever use one? No, I would not, because it is immaterial who first used it. What is at issue is how I use it. Likewise, many false gospels think of Mary, mother of Christ, in an idolatrous manner. Does that mean that from now on I should not call Mary blessed because of their idol worship of her? Again, what they do has no bearing on my understanding of her blessedness, or in the right way to think of her in serving God. It is what I do and how I believe that counts. It is not the cross, or the tree, the plastic star, the gifts, or the meats offered to idols, it is what is in the Heart. It's what is within a man that makes a deed unrighteous, not the tree that stands outside of him. God has made that perfectly clear before. It is what is in a man that defiles him, not the Christmas tree setting on his porch.
Some feel they can serve God well and bring Glory to Him by having a Christmas tree, as a symbol signifying Christ's birth to all who would see it. And there can be no doubt that Christmas keeps Christ's birth prominent, even in the world. Yes, even the wrath of men praises God. And to the Christian it is in honor, and for the glory God. Every day is a celebration of Christ's birth, but this special day of observance of the gift of God to men, can be very noble. The fact is, if Christ be the root of your Christmas tree, then the tree is a symbol of that planting, and the decorations the tokens of the beauty and brightness Christ brought to the world, and the gifts a representation of our charity, which is the greatest gift God has bestowed upon us. So then what evil can this celebration be? Do we think that the magi who gave gifts, in honor of the King, would today be condemned? I would say, Probably! Just as the woman who brought perfume for the feet of Jesus was judged unrighteous and condemned for her actions. Because man does not look upon the heart. There is no evil in an action not condemned by the law. There is no question but a Christmas tree "can" be used to commemorate Christ in faith. That is not to say it always is, but it can be.
Nevertheless, whosoever cannot understand this principle, or who feels in his heart that this is improper, then they should not use a tree in celebration of the nativity of the Lord. But it is not inherently evil, it is in fact simply a piece of wood. So judge not another man's servant (Romans 14:1-6), because to his own God he stands or falls.