Then surely you can give us one scripture that says that?
The only things that the word says to observe are God's appointed days (Pascha, First Fruits, Pentecost, Attonement, Tabernacles...)
You do not have to celebrate the Resurrection of the Messiah, Jesus Christ, Second Person of the Blessed Trinity.
But claiming such a celebration is not Scriptural is absurd.
Where did "the word" tell Simeon he would not see death before seeing the Lord's Christ?
Can you give me sola scriptura where it says that Scripture alone should be our sole authority? Tradition plays a significant role as well.
2 Thessalonians 2:15: "Therefore brothers, stand firm and hold fast to the traditions you received from us, either by word or by letter."