If We Shun the Trinity Because It's Unbiblical, Then Why Not XMAS?

[stmatthew]

Luk 2:8 And there were in the same country shepherds abiding in the field, keeping watch over their flock by night.
Luk 2:9 And, lo, the angel of the Lord came upon them, and the glory of the Lord shone round about them: and they were sore afraid.
Luk 2:10 And the angel said unto them, Fear not: for, behold, I bring you good tidings of great joy, which shall be to all people.
Luk 2:11 For unto you is born this day in the city of David a Saviour, which is Christ the Lord.
Luk 2:12 And this [shall be] a sign unto you; Ye shall find the babe wrapped in swaddling clothes, lying in a manger.
Luk 2:13 And suddenly there was with the angel a multitude of the heavenly host praising God, and saying,
Luk 2:14 Glory to God in the highest, and on earth peace, good will toward men.

The angels rejoiced and praised God his birth, so I see no reason why I should not.