Where in the Bible does God tell us not to celebrate Jesus' birthday, but His death, resurrection, and return? Are we really not to celebrate Christmas as Jesus' birth?
Your question is backward. God told us everything needed for life and godliness (II Peter 1:2-4). "Everything" leaves nothing out. So the question is not "where did God say not to ..." It is always the question "where did God say to ..." See: Holiday Observances.
"Do not add to His words, lest He rebuke you, and you be found a liar" (Proverbs 30:6).